Metformin Smelling Fishy? What You Can Do.

Researchers have discovered what many people with diabetes have known for years: The popular Type 2 diabetes drug metformin (brand names Glumetza, Riomet, Glucophage, Fortamet, and others) has a distinctive scent that, for some people, is enough to cause them to stop taking it. But as the most widely prescribed diabetes drug in the United States, metformin plays an important role in helping people with Type 2 diabetes control their blood glucose levels, and experts have suggested several solutions for dealing with the medicine’s unique scent.


In a letter published in the Annals of Internal Medicine, physicians from the Medical College of Georgia described two adult men with Type 2 diabetes who complained of a “dead fish” odor of metformin that had led both men to stop taking the medicine. Searching the medical literature for more information, author J. Russell May, PharmD, and colleagues found no reports of this issue. Upon searching the Internet, however, the researchers came across hundreds of message board posts referencing metformin’s odor, and an informal survey of pharmacists found that many could identify the medicine by its distinct smell.

May and his colleagues wrote to the journal to raise awareness of this issue and questioned whether nausea, one of the most commonly reported side effects of metformin, could in some cases in fact be a reaction the fishy odor. May noted that “Metformin is an excellent drug, but the immediate-release formulation may have an odor to it. The smell is fishy or like the inside of an inner tube, and in a patient’s mind…they may think the drug isn’t good.” (A manufacturer of metformin notes that there has been no association between the odor of metformin and its effectiveness.)

The authors indicated that switching to one of the extended-release versions of metformin, which have much less smell (if any), solved the issue for one of the men described in the letter. (The other man refused to try the extended-release version.) The researchers suggest that anyone with a concern about metformin’s scent should not stop taking the medicine but should speak with his physician about the possibility of switching to a different formulation. Another solution proposed by May is for people to hold their nose while taking the drug.

For more information about the doctors’ findings, read the article “‘Fishy Smell’ May Keep Patients From Diabetes Drug” or see an excerpt of the letter in the Annals of Internal Medicine. To learn more about metformin, click here.

Have you noticed an odor to your metformin? What, if anything, have you done about it? Let us know with a comment below!

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  • Randy

    I have had Glucophage (Brand Name), and noticed no smell. Since then, I have started purchasing generic Metformin from $4 list at Wal$Mart, and have got different “versions” from different manufacturers. One of these, (I don’t remember the mfg.) Smelled very bad, fishy. This was one where the pharmacy had put 3 months worth in one huge container, so I am assuming they had a large bulk container and had to count out the pills. My latest refill was from a manufacturer i had had before, and was pre-packaged by a month’s amount, so they only had to take the bottles off the shelf and put on a label. These do not have a noticably bad odor. But I have never have had any aftertaste from any that I have noticed… I am under the impression that generic versions of the drugs only have to have the active ingredient be the same, generic mfg’s can and will change the non-essentials, such as color, flavorings, filler, etc. Maybe this is only from a few mfg’s? Anyway, Stay on your Meds, everyone!!!

  • Diabetes India

    Part of what you have mentioned is correct. Some people do complain of “uneasy feeling” when it comes to metformin, when they get started on treatment. But later on, probably due to the upregulation of taste receptors or smell sensory receptors, they do not feel that uneasy feeling (reported in some as nausea, fishy odor, typical odor). So mostly the coninued use of metformin over the time has overcome the odor problem. Extended release version has been used not so frequently w.r.t. regular metformin. But this data is interesting to understand from the compliance point of view in diabetics.

    Diabetes India: Promoting Healthy Diabetes Life

  • Deb

    The extended release form smells bad, too. I get it down as quick as I can.

  • James

    I have been taking Metformin for about three years and am really getting sick and tired of the putrid aroma. Luckliy I found that the manufacturer Apotex made a generic without any smell! Too bad for me they have numerous recalls and the brand is no longer available at any pharmacy around me. Not only do these pills stink, they make me smell and make my perspiration stain white clothing. Nasty business. Can’t any of these scientists figure out the issue and work a solution to the stink?

  • Peggy

    I have noticed the odor from the first time I started taking Metformin. I just swallow mine as quickly as possible and try not to breath as it is going down. I have written several times about it to different publications and manufacturer, but I guess nothing can be done. I’ll just continue taking it because I know it’s doing me good.

  • Ed

    Have been taking Met for 5 years and have noted the fishy smell. Just ignore it and have had no adverse reaction and tupe 2 is completely under control

  • DeDe

    I took Metformin for several years, having the prescription filled monthly. Then with a change of physicians, the prescription was filled with a three month supply. That is when I noticed the putrid smell coming from the pills. It wasn’t fish, it smelled like an unclean urinal. The urine smell was overpowering. I am so glad to be off Metformin and on to other medications.

  • Henry Mendoza

    A more important issue questionably not being covered: in June 2009, the American Diabetes Association reported at their annual conference in New Orleans that 75% of patients on metformin develop peripheral neuropathy within the 12 months of starting metformin. Why isn’t there more coverage on this issue? I developed “PAINFUL” peripheral neuropathy 3-4 months after starting metformin. I took my self off the medicine, and the pain has subsided. But the damage by metformin is done. Why hasn’t this “association” provided more public awareness?

  • Doris

    I take Metformin and my complaint is after I take it I notice this bad smell in my urine. Hard to miss the odor–its strong! I take the pill with my morning oatmeal so I don’t have any trouble getting them down but sure notice the odor when I open a new pill container from the drugstore. Since it smells like the odor in the bathroom–voila! I am pretty sure its the Metformin.



  • maria alvarez

    I have notice the smell recently when i open the bottle it’s bad , i take what am going to use and lay it down for a minute before i take it, then i take it and there no smell going down.

  • JOE


  • Don

    Having Type 2, I take metformin. I have noticed the odor for years. To me it has a chemical odor.
    Fresh fish has a much different oder.
    Once when I picked up my generic order they had filled the bottle with pills that had the aroma
    of alomonds or hazelnuts. Only got those once in ten years. Really did make a difference when it came to taking them. So something can be done
    about the aroma, if the big drug companies cared.

  • Wayne

    Close the bottle quickly. it leaves the odor in the bottle I have been taking it for over 4 years, with excellent results. I can tolerate the odor, because it has been keeping my blood sugar under control, and preventing the use of insulin.

  • Sharey Travis

    I have taken metformin for 3 years and have never once noticed any odor. It keeps my numbers where they should be.

  • Jeanette Simms

    I have been taking metformin for over a year and have never noticed any odor. I just now checked my bottle to make sure and had my husband sniff it as well and niether one of us noticed any odor. If it makes any difference, I get mine filled at Walgreens. I wish good luck to those who are having problems, but so far all is well in my medicine cabinet.

  • Dianne Lapolla

    I have been taking metformin for 4 years. Last summer had my perscription refilled and the pills had a very, very fishy odor. Not only that, but I could hardly swallow them the smell was so bad. My skin was also really itchy and my stomach was always upset. Had to get a special lotion from my doctor for my skin. I took the pills back to the pharmacy, told them of my problem and they said that all metformin had a fishy odor; nothing was accomplished. So I called the pharmacutical company and they called my pharmacy and found out that this was the first time I was given this brand (same company, different brand) The old brand,which is pre-packaged, was ordered and it is odor free. Problem solved! So there is an odor free brand.

  • Felecia

    Yes, I have been smelling the fishy metformin for several years now. Why does it smell fishy and what can be done about it. I just can’t believe that these pills leave the lab smelling like fish. I can’t stop taking them b/c they smell this way, but b/c there are no alternatives.

  • di hal

    I’ve been taking this drug for 6 years and I do not smell anything at all!!

  • Allen

    I have been taking Met for almost 3 years and haven’t noticed the odor. I, like Jeanette, get mine filled at Walgreen’s. However, I have noticed a number of bouts of stomach distress!

  • William

    My problem is metaformin results vary from batch to batch. Some knock down fasting sugar and some do not, Other times,diarrea, sometimes not.

    Urine oder varies from batch to batch as well. I thought it was my BP meds, but now i think it was the metaformin.

    Started taking one gram of chromium picolinate, prior to one a day insulin. With this current batch of metaformim, my fasting sugar is 35 points lower.
    Having tried it with daytime use (with metaforin)I found severe drops of as high as 75 points from fast sugar.

    I do not think it wise to try chrome without testing blood 3-4 times a day. hypoglycimic (low sugar) reaction appears possible.

  • gayle

    I take Metformin ER and have not noticed any fishy smell or odors from it. I do get mine from Walmart

  • Jeff

    All I know is that my cat comes running over and is intently interested in my metaformin pills. That is when I first equated the smell with fish. Never bothered me but it sure has the cat’s attention.

  • Bill

    I began taking metformin a year ago. I noticed the “fishy” smell, but it did not bother me.

    I also track my fasting blood sugar every morning.

    After about 6 months, I began to notice that some bottles of metformin (Sandoz from WalMart) had a greater smell and others had none.

    Then I noticed that my sugar levels were down when taking the more smelly pills and sugars levels were higher when taking those without smell.

    I even returned a half full bottle of no smell to the pharmacist for some that smelled and my sugar levels dropped 15-20 points on average.

    For me, the worse smell the better!

  • Kathy Force

    I have taken this drug for years, and I have never noticed a smell.

  • Lisa

    I first noticed the fishy smell when i started the drug 4 yrs ago. I googled it and other’s were experiencing the same oder. The issue for me was not the oder as much as a few yrs later the depletion of B12 in the body that Metformin can cause. I experienced sore swollen tongue. Did some online reserach, spoke to my Dr and started taking B12 orally. Luckly my Dr knew about this side effect. Some Dr’s do not.

  • cozetta fields

    this med causes me to feel very tired and causes a large amt of explosive gas in my digestive tract. also lots of bloating. sometimes i take it and it helps, sometimes, it dosen’t make the blood sugar go down.

  • Debbie

    Peripheral Neuropathy caused by Metformin was discussed in a recent article I found on the Google home page. The article claimed that metformin causes a B12 deficiency which in turn causes peripheral neuropathy. It said to have your doctor run a serum B12 test to determine if you have a deficiency. You can request that your doctor give you a B12 shot or you can get B12 supplements.

  • BA

    Yes, I have noticed. The pharmacist said he could not smell anything, but replaced the Rx. The replacement had the same problem I had never heard of this, but it has been a problem for me only in the last few months. The first thought was that the medication had deteriorated. Perhaps some people cannot smell it? It is not always present.

  • phil

    I’ve been taking Metformin (1,000 mg 2 x day) since I was diagnosed over 2 years ago.

    I originally got 30 day scripts from Walgreens, then started 90 day mail order supply through my insurance. Now I get a 90 day supply at K-Mart for $10.00.

    There have been multiple manufacturers over that time. One time my script was filled with pills from 2 different manufacturers. I have never noticed ANY smell from any of the pills.

    The drug works great for me – with no complications. This is the first time that I was even made aware of any issues other than some people who have digestive problems when taking Metformin.

  • David Dallas-Midgley

    Yes, it does have a fishey oder.

  • Mike

    I too have had batches that smelled like a heavily used catbox. And I’ve had some that had no odor at all.

    The most recent bottles are from Medco out of Dallas but filled in Juarez, MX. They are quite toxic.

    What I do is put a moisture packet in the bottle and the smell is reduced considerably.

  • Wanda Pulliam

    Yes, the smell is terrible. I had been taking the extened release and my doctor wrote my prescription for the regular metformin. When I got my medicine, I thought I must have the wrong medicine. I called the drug store to check and was informed that the prescription had been written that way. I checked with my doctor and he advised he would change it or I could contine taking as written. I thought I could stand it for 3 months but I was so glad when my 3 months was up.

    It smelled like fish, but maybe really bad fish. Now I can hardly stand to pass the fish at the grocery. I held my breath when I swallowed mine. I’m back to ER, thank goodness.

  • Bill Knapp, RN

    I take metformin 2 times a day, 1000 mg, both times. Even on smaller doses the fish smell is pervading. It cause my urine to have a fish smell that is quite strong and I hate it. I don’t know why the FDA would every deny or ignore what all of us taking this medication know. It smells like fish in a big way!!!

  • Jarrett Anderson

    I have been using Metformin for years and have never experienced a “Fishey Smell”

  • Elizabeth Arsenault

    I’ve been taking metformin for almost a year and never smelled any type of fishy smell. It doesn’t upset my stomach either. I take it with food like it recommends. I purchase the $4 metformin from Wal-mart and always get the same company and no problems. Why can’t they put a coating on the pills like some other medications do? That should help with the smell that some claim to smell and it would make it easier to swallow too.

  • Pat Davis

    I’ve taken Metformin for at least 6 years and yes, there is a horrible odor. What I finally found is that I now put my pills out in a 7 day container/pill box and that seems to help get some of the odor out at least for swallowing/getting it past my nose. I do notice an odor in my urine but that seems to happen with most medications and/or supplements. I drink at least 60 oz of water a day which seems to help a little with that too.

  • Robert l Pann

    Metformin smells fishy for sure. I just place the pills on the table for a while than i take them.

  • Robert Bryant

    How embarrassing to stand at a urinal (ball park, or some other public facilities) and note others nearby almost puke at the smell eminating from my urinal. If I do not take my 1000mg twice a day during a meal, I often have bad cases of diarrhea. I’ve always accepted these frustrations as part of being diabetic. I’m heading to my doctor for a change soon!!

  • R Lauterbach

    I noticed the fishy odor upon switching to the Metformin generic formula. I take 2 tablets a day, so the odor from the 90 day supply is quite strong.
    To help avoid the unpleasantness of the odor, I purchased a monthly pill organizer. I put 2 tablets in each section, I then have to open the 90 day supply bottle only once a month. I make sure I fill the organizer hours before having to take a dose. On a daily basis, I do not notice the fishy smell at all.

  • Jayne Black

    Have been taking Metformin for 5 years in the 500 mg pill, 3 times a day, with food. Have been getting it from Humana/Right Source 3-month by mail and Walmart Louisville, Ky and Clearwater, Fla. No smell, no problems, no complaints, good results, no change.

  • Harriet J Seabrook RN

    Metformin most definitely has a strong fishy odor, esp. the generic versions. I have been taking it for 1 year. A client reported that her OB/GYN prescribed Metformin for increase fertility and to regulate her menstrual cycle.Check out the side effects of this drug. It has really decreased my glucose levels while increasing my libido also. FDA needs to investigate.

  • Margaret Wade

    Since I started taking Metformin 4 years ago, I have had trouble will my leg and sometimes my arm aching like a toothache. I told the doctor’s assistant and she told me to see a muscle specialist. I will be requesting to see the doctor when I go in May to see if I have vitamin B12 deficiency. Also, the pharmacist change the manufacturer and the Metformin does not smell but it seems not to control my blood sugar as the other brand does.

  • Gil stallknecht

    The past year the metformin I get does smell like innertube or fishy. I take it out of the bottle it came and use something else. I still take it, but do not like the smell. I get mine from the VA.

  • Judy – northwest PA

    i take 4 of those suckers a day,, 2 in the am, and 2 in the pm,,
    the last few months i have gotten them at giant eagle,, the smell is nauseating,, and i dread everytime i need to take them.
    i don’t know what to do,, it is so hard for me to take them. i don’t know if i call the pharmacys and ask them to smell the bottle before i get my refill, i will try leaving them set out for awhile before i take them,, it’s worth a try.

  • Ruby M

    Henry Mendoza.
    Please provide your source/article/magazine for Feb. 24, 2010 comment regarding Metformin and peripheral neuropathy announcement at ADA annual conference. I am about to begin taking Metformin and would like to have the info to back up my disucssion with my physician. Thank you.

  • keysona

    Yes, Yes, Yes. there is definately a dead fish, fishy smell to metforme. I had to hold my breath when I opened the bottle. Thank goodness my doctor took me off of it. I’m trying to controled my blood sugar with diet, so far so good.

  • Anita

    I have also been taking metr for like 10 years, I got started smelling the odor just this last 3 years. I have not been taking they like I should and my blood suger are HIGH in the 405mg. Not good at all.

  • VJ Cordova

    I knew I smelled something! My husband always says I “breathe too deeply”….but a few others do too. Metformin does smell strongly, I’m off it now, thank heavens.

  • Ivernia Schwartz

    I’ve noticed the smell but the smell doesn’t upset me in anyway but I often wonder what it is made of to be so effective in helping the diabetes.Just what is it made of to smell the way it does.
    I can’t take many other medicines without an allergic reaction but this doesn’t bother me so take it even though it has a smell.

  • Pam

    I was overwhelmed by the smell of this medicine, as well. So, my doctor switched me to the ER version…and voila’! No more odor!

  • Larry

    I’ve been on metformin for a few years now, but only noticed the smell recently. It’s not noticeable when I open a new bottle, but is present within a few days. Considering some of the issues I’ve had with blood pressure meds, a fishy smell isn’t much to contend with. I’m just happy the stuff works.

  • Marty K

    metformin has always smelled like fish or inner tube smell no big deal just swallow and it’s all gone

  • Vicki

    I have not noticed a smell, but have to wonder if there’s more to it than that. I have always hated fish and this medicine is tearing up my stomach.

  • Kj

    I have celiac disease among several others. Along with many other medications I take I recently started metformin (in the beginning of shingles for the third time)….not exactly great timing but then again when is good timing?

    All medications have their share of side effects but the real question is whether or not it is helping in your condition. I try and wait a while before stopping a new drug. Having major gastrointestinal problems with very damaged intestines I can’t tell anymore if it’s medication, a virus, or just my body and how it does not function properly. As for the fish smell I’m not sure. I just the medication and hope it will work in some positive way. It’s too tiring being sick all the time.

    I don’t know if any of this helps but I am a 37 year old single parent of a child with Tourette’s so we have our fair share of hard times so I just try and stay thankful we have some type of medical insurance and keep up with our doctors often.

    ~Best wishes to all of you

  • bill

    Yes. Mine (Teva) has a very bad smell when opening the plastic bottle. I stopped taking them yesterday until I did some research — I took one this AM. I am not sure but it might be causing some degree of back pain also — on the left side just under the ribs. Bill

  • Mimi Malone

    The first two prescriptions I had filled had no odor at all – the last batch smells PUTRID – but I don’t taste it because I swallow all pills quickly (put water in my mouth, hold it there, add pill, swallow, more water). HOWEVER I am so relieved to read here about the STINKY URINE. This is a new development and I can’t get in to see my family doctor for a month. I thought my kidneys were rotting away or something – relieved INDEED for this info. THANKS!!!

  • James

    I too find metformin smells unpleasantly fishy and lately my urine has a disgusting odor. Thanks to the people who who have contributed to this discussion. My next discussion is with my doctor.

  • Cheryl

    I’m glad I found this article! I thought I was going crazy, every time I would open the drawer with my prescription drugs in it, I smelled this putrid fishy smell. I cleaned out the drawer and still the smell came! Because I take other pills with the metformin at the same time, I didn’t realize the smell was coming from the metformin! This morning I opened the bottle of metformin and brought it up to my nose and WHEW!! Gross! At least now I know where the smell comes from. I haven’t noticed any of the other side effects people have reported, but will watch for them now!

  • Jackie

    I am suffering horribly with the “fishy odor” syndrome since taking Metformin. It first started by making my urine smell fishy. So, I experimented by not using it for it a few weeks, and the odor went away. I stared back and the odor returned with a vengeance. It is so bad, I am beginning to think it is causing me to have a yeast infection.

  • Pat

    I’ve been taking Metformin for about five years now. There was never any kind of smell to them. I got my prescription filled yesterday, at the same pharmacy I always do, and when I got home and opened the bottle there was a strong odor of fish. I was afraid to take any because there wasn’t supposed to be a smell. I called the pharmacy and they just told me that the pills were derived from fish and they always had a fish smell. I’m leaving the cap off now to try to “air them out” but I don’t know if that is going to work. The pharmacy said that they didn’t change companies, but a friend of mine told me that her boyfriend had the same smell to his pills. I know that they work, so if this is what they’re going to smell like, I’ll just have to get used to them.

  • Jennifer Ovink

    CVS pharmacy puts a small packet of charcoal in each bottle of metformin (I take 850 mg regular, not extended release). I never noticed a smell and thought the desiccant was for freshness. However, when I recently filled the prescription at Rite Aid, I immediately noticed the dead fish smell. So I transferred the desiccant charcoal packets into the Rite Aid bottles and within 2 days, the dead fish smell was GONE. I called Rite Aid, but they told me their autofill machines could not handle the charcoal packets but thanks for my suggestion.

    Harumph! It’s a good solution for anyone who has to take this putrid-smelling medicine!


    I have been taking metformin for two years and have never noticed a smell till the last batch – I thought they must be “off” but see this is a common problem. I believe it must be the brand the drugstore dispenses because I have never had this problem before. I will ask for something different next time.

  • Mara

    I took Metformin for six months and it worked so-so for my sugar levels. It was not stinky but did cause stomach upset if I took 500 mg at one time, so I usually cut the pills in half (not ER Met). One refill did stink and it was TEVA manufactured, so I got a different manufactured pill and it didn’t stink. It also still didn’t work really well (but that could be from cutting pill in half).

    My doctor switched me to Fortamet (which is metformin that is supposed to be kinder to your stomach) which I take before bedtime. It still causes mild stomach upset and the pills do smell. I take the pills with either skim milk or Vitamin water so there is some flavor to block the smell (and I’m getting a few carbs, which I’m advised you should do when taking the pills). Amazingly enough, my morning numbers have gone down into the 120’s (from usually being 140 or higher in the morning). So the pills are effective. I will try airing them out, too, and adding a dessicant. Thanks for the advice!

  • Janis Ireland

    For years my Metformin didn’t have an odor or taste.
    During the last year, however, whatever I was getting from Walgreens had a horrible odor AND taste. I wanted to vomit when ever I had one in my hand. I put up with it. But today, when picking up my meds, the Walgreens person at the driveway commented that they were going back to their old supplier. They had had a new one for the past year. I am wondering why it smells and tastes so bad. So happy to go back to the older, regular Metformin. What I want to know is was there something wrong with the other forumulation?

  • Janis Ireland

    Just wanted to add to my previous comment of a few moments ago.

    I did not notice a fishy smell or taste.

    BUT I noticed a horrid over perfumed smell and taste. I’m 59 years old and have taken lots of meds thru the years that didn’t taste good or smell good. But this is just overwhelmingly bad.
    It really makes you nauseous. Just one whiff.

  • sheila seeholzer

    I have taken Metformin for several years. The last few months I smell like strong rubber or a smelly bathroom. I shower twice a day and use body spray or perfume. It is annoying…

  • Susie

    I can take the smell of the pills if I don’t inhale while I’m taking them. It’s the smell of my urine that I can’t take. The smell can linger even after I’m done using the facilities and quite frankly it is very embarrassing.

  • Katie

    While I have experienced positive blood sugar control using Metformin, the urine smell is incredibly embarrassing. I am reluctant to use the public facilities at work out of fear that a colleague will associate the smell with me, and cringe each time my husband enters the bathroom after me.

  • Patricia A. Vaden

    After urinating about three times; I have to wash up because the smell is really bad. I wash up about 5 times a day on average, because I take water pill everyday. I drink a lot of water to help keep the odor down some. I can’t open the bottle close to my face, because the smell is unbearable.

    Posted by Patricic / April 13, 2011 at 09:21

  • Ramona

    I was told by my pharmacist to store my Extended Release Metformin in the freezer. Not all medicines can be stored in the freezer, but this one can. It works….no odor.

  • R J

    I take Metformin Hcl, the pills smell and it gives me bad body odor.

  • GnarlyOne

    I am diabetic and use Metformin. I have used Fortamet as well. Both give me a terrible body and urine odor. This has been for years. In googling I find it is wide spread.
    Okay, what is the solution? Stop taking it is not the solution.
    I have read that using anti-bacterial soap helps. Another idea is bathing more often but how often is needed to get relief from this nasty odor?
    Lets beat this problem! 🙂

  • Donna Oyama

    I have been taking metformin for over 2 yrs. now. They always had a urine odor. It was keeping my blood count down, always under 100. Two months ago the pharmacy switched mine to a different manufacturer;(Aurobundo). Since I’ve been taking this one my counts are always over 100, generally 115 or 120 range. I’m trying to get the other company I had before, my pharmacy is checking on it for me. Mabe this is the problem, the more the odor the better it works. Mabe the others are too synthetic, or just compounded up differently. Doctor says every individual is different in absorbing these meds. I will not complain if they do the job. Good luck to all !!

  • Jeff Audet

    The fishy smell of the pills has never really bothered me, but my latest refill seems to be made with a chemical intended to mask the odor. It’s supposed to smell like raspberries, I think. The fish-raspberry combination is truly horrifying.

  • frankie

    What would be most useful is if everyone would write the specific name of the pharmaceutical company who made the metformin. Buying it at WalMart or any other place does not tell us where the med is from, only who is filling the bottle. This should be on your med bottle, who manufacture’s it. That way we can look up where it’s made perhaps.. like Mexico vs USA, vs China vs Canada. Also what is the ingredient in this that causes the fish smell to be so severe in some and non-existant in others?
    I’m getting ready to start this metformin in a couple days. I have a close-pin ready.

  • frankie

    So far in the comments I’ve read that these stink: Aurobundo; TEVA, Medco (Dallas via Juarez MX); Sandoz.

    So far I’ve read in the comments that these have no smell: Humana/Right Source.

    Other than the person who posted the MX connection, we don’t know where these where manufactured. This is basic information that we should know, and should be available at the FDA website, perhaps.

    Basically, if it stinks and works.. ok by me. But if it’s too extreme a smell… we need to have more answers from the companies that makes them.

  • frankie

    To my wonder my meds arrived in the mail today. I opened the bottle up and zero aroma. No smell whatsoever. FYI: the med was filled by a Rite Aid in the state of Maine, Metformin HCL 500mg tablet, round, white. The brand is AUROBINDO PHARM. So again, no odor in this prescription.

    I noted someone commented previously about a ‘Aurobundo’ that had an odor. The spelling is close but my AUROBINDO was perfectly fine.

    Good luck all.



  • Father Deacon John

    I think that the smell isn’t so much the issue. The issue is that no one can answer the question of is Metformin made of any fish or shellfish or seafood. Allergies to these are a problem. My pharmacist is calling the companies to find out. I had swelling in my limbs which stopped when I stopped taking Metformin. Choose your poison carefully!

  • Carolyn Dooley

    My Meformin does have a fish smell. Also, my urine smells horrible. Father Deacon John please let us know what your Pharmacist finds out about this Diabetic Type 2 medication.

  • Jean-Guy

    I have been on metformin for 30 years.Cannot remember a bad oder like the last year or so.Iwill stop taking them they are making me sick. they smell like old urine and make my urine smell strong.Are these companies trying to poison us.

  • Allison W. Cone

    I have been on Metformin/Glucophage for about a year now. Tonight when I opened the bottle it smelled fishy to me. It’s not a new bottle. It’s not an old bottle. I’m about half-way thru a one month supply I got filled about two weeks ago. So, I googled “what is glucophage made of?” and got this very page as one of the top ten hits. Go figure.

    I know that Premarin used to be made from concentrated mare’s urine (it may still be for all I know). That’s why I want to know what Metformin is made of. There’s no warning on the label about seafood allergies. What gives?

  • jim snell

    If it was a piece of fish, you could soak in wine and lemon juice.

    I have noticed in past some of the generic versions of met do have an odour. Otherwise pinch your nose and swallow.

    Been on the stuff for years.

  • drandolph

    I have taken Metformin for at least 15 years. It has never smelled until my refill this month. Smells terrible. My urine also has a strong smell now. I’m able to get it down.

  • Susie

    I stopped taking Metformin because it gave me the most awful body odor, as well as smelly urine. I never noticed the smell of the pills but after months of trying to figure out where the terrible body odor(urine smell + fishy smell) was coming from, I decided to stop taking Metformin on my own. Slowly, the foul body odor went away. The medicine works for lowering blood sugar, but it makes you and your urine smell worse pretty bad.

  • Gloria

    Yes I have noticed the smell On metformin but not only that .
    It makes my urine smell just lIke the pill smells and it makes me smell bad as well. I shower and the minute I pee I smell again and I feel very uncomfortable with the ordor I have to deal with.


  • noritae

    Talk about smell! I went to a public restroom just to pee. When I got out the next person went in and back out immediately. She had a face on her like she was really disgusted. I also noticed when I went to the restroom at work, no one would go behind me. I promise you, I take a bath put o perfumes, I try everything and it does not make a difference. I wish they would come up with something better.

  • Jenny Monk

    I have been taking metformin for many years & I cant stand it any longer!! Besides the smell of the pill, it smells like that when yiou pee. Also, if you get a few drops on your panties they smells like that.I just got my Dr. to switch to ongylz, no more smell-so nice- thanks

  • Kitty

    I have not been able to wear anything that smells good on me while taking 850 mg of Metformin.

    Scents that I used to get compliments on now smell bad on me. Poeme, Coco or other Chanel perfumes.

    Would the slow release Metformin cost more?

    Thanks for responding.

  • James

    It stinks.

  • Bruce

    The fishy odor can be almost completely prevented or eliminated by adding canisters of activated charcoal (looks like black sand) and silica gel. I get the activated charcoal canisters from bottles of Ecotrin or enteric Bayer aspirin and the silica gel from bottles of Niaspan, but other drugs may have these as well. Place one canister of each in each bottle of metformin that you have as soon as you can. Noticeable odor is usually gone in a couple of days. The canisters can be used several times but should be replaced when they lose effectiveness.

  • al

    it does smell like an unclean female sex organ. fishy. salmon.

    and it tastes so sour.

    gross metformin. but it works for me. mine come from walmart and i think they say h 302 on the pills… if im not mistaken.

  • Basu

    I just started taking metformin 500mg Mfr: ZYDUS Pharmaceu, Store: CVS, about a week, on 3rd day; I noticed the rotten fish smell in my urine. I decided to visit Doctor again but before that I started drinking more water and found smell subsided. So I also noticed darker the urine become, the more it stinks. However, this site helps me understanding the problem well but since I am new to this medication so I will visit Doctor next week. Thanks to all posters here.

  • Jocey

    My cat LOVES it when I am counting out my meds! I’ve considered sharing Metformin with him but have decided not to…but he sure loves to climb all over me while I have pill bottle open!! Fishy fishy…



  • Theresa P.

    I have been on Metformin for many years now. I am not diabetic, but It has been prescribed to treat severe poly-cystic ovarian syndrome. I have had many different brands and found that only the ones that smell like “fish food” cause stomach upset. I now take aloe vera capsules once a day and it helps to counter the diarrhea and nausea, but doesn’t get rid of it completely unfortunately. When I use the aloe with the “normal” smelling pills, I am great and have no side effects. I also notice that with the smelly pills, any light color plastic my skin touches for more than a few minutes turns blue. Any ideas there? I am completely at a loss. The pharmacy I have been using just got in these smelly version pills after about 2 years of normal and suddenly I am having all the same problems that I did when I first started taking it. If anybody else notices the same, or has the blue plastic reactions, please let me know.

  • Joyce Stokes

    I got prescription re-filled last week. The latest refill has fishy odor. The previous one did not. I have previous bottle as proof of this. What is difference in extended release and not extended release? My doctor calls in order to pharmacy so would that indicate he is ordering extended release Metformin some of the time and not other times. Would be interested in anyone’s comments.

  • Alan McCusker

    When first prescribed metformin I noticed the foul smell & taste right away…Then several months later the pills were changed then again a yr later they were changed again …This last batch has a metalic “penney” taste and soon after gave me stomach upset …I quit taking it and never felt better…just watching my diet …who needs pills that make ya sick !!

  • kayley m.

    i recently started taking metformin and the smell hit me the minute i opened the bottle! i tossed it to my hubby and told him to smell it…he actually gagged. we decided it’s not just fishy but compounded, dead fishy, like fish food. it’s really awful. i’ve also been having awful stomach aches and heartburn/GERD since i started taking it. but, since my sugars are just under 200, rather than over 300, sometimes 400…it’s all a tradeoff.

  • Angela

    I just started taking metformin. I don’t smell it when I take it. I smell it when it secretes out my pores thoughout the day. I didn’t know what it was in the beginning. That’s why I looked it up. I smell like an old person that hasn’t been bathed in a while. It’s embarressing.

  • Mike Robertson

    Oh my gosh people! It’s not that bad. I notice the smell when I open the bottle. Big deal! I swallow the pill like any other. I’m just so glad to have something that has helped me so much.

    • Geriinct

      It’s not so much the pills smell…It makes me smell real bad…I shower all the time but the smell sticks to clothing also including my overcoat.

  • robin

    I’m sorry I’m a late complainer. I wish I new the other manufacture of the metformin I took before because I sure would like that one back. I have such a bad odor when I pee, my fellow workers that use the bathroom at the same time have commented about the odor ( how embarrassing) now I have to dash in and out, hoping no one comes into the other stall. There has to be help. Please let me know. And oh the other pill I belive was a different shape. How embassassed!

  • Robert Nelsen

    I thought I may have had a contaminated batch of Metformin when I first started taking it. It indeed smelled like dead fish. I asked my Pharmacist about the odor and he said it was typical of the drug. As long as I don’t sniff the container, I’m good with it. I still can’t help but wonder what makes it smell so bad. Can anyone tell me?

  • Catherine Wells

    I didn’t notice the odor when I was the 500mg twice daily, then when I was switched to the 1000mg twice daily I noticed the terrible odor it is enough to make some people gag. It doesn’t really bother me, just hope it doesn’t make me smell like that. I have fun with it and ask people if they smell anything and hand them the bottle, they take a big whiff. Whew.

  • dee

    Those who have written about the fish smell are right, its a very strong fishy smell,even with the slow release one. It also effect the body function which goes though the body and smell the same. Another which make me wonder what are the ingredient, because my doctor made a mistake when she told me to take 2 tablet morn. + 2 at night in which i was taking 1000mg already,making it close to 4000mg. I was feeling dry inside and out. I still don’t trusts it.

  • Gary

    i notice a slight odor (Medco provided metformin) to the pills when i take the cap off the bottle of pills – but it is not overpowering or nauseating. i simply take my pills and be done with it. i DO notice that at some point after taking these slow-release capsules that my forearms and hands acquire a distinctive smell which on occasion vaguely resembles fish but which can also be indeterminate , but ‘different’ and not offensive. it seems to be coming thru the skin , similarly to when having eaten large quantity of kimchi ( Korean pickled cabbage) or, for that matter, skin saturated garlic (especially when only lightly cooked). so, for me, the scent is noticeable – but not overpowering or nauseating or offensive. i just hope no one else notices it! sorry to hear from some of you that your coworkers have noticed it… good heavens. well good luck to all and i hope future metformin formulations are less of a problem for you all.

  • Connie

    I always bought my Metformin from Walmart. It came in white bottles of 30 made by Sandoz. Recently I had a prescription filled at Walmart. They are not buying Metformin from Sandoz. The pills now come in brown tube like contain.The pills smell. They don’t smell as bad as some that I had years ago that smelled fishy but these do smell. I wish Walmart would go back to the Sandoz tablets. I went to CVS to ask if their pills are in the white bottle and it appears they have the same pills as Walmart in the brown plastic tubes.I am so disappointed.

  • Mary Osorio

    I refuse to take Metformin due to the unbearable smell. I will follow up with the extended release odorless version. I wish my physician would’ve warned me about the odor. I would’ve asked for a different medication.

  • Ululani

    I have been on Metformin for years and have not experienced bad odor in my urine until my doctor changed the milligram from 500 to 850. It was then that my urine smells so bad that I try and not to use the bathroom at work. It’s embarrassing! It makes me want to vomit. However, I have read all the comments and will try some of your suggestions on ways to get rid of that awful odor. If it doesn’t work I will definitely consult my physician.

  • mkrause

    We just received Metformin that is required to be ordered through the mail. Previous batches have not had any odor, but these pills manufactured by Sun (Caraco) smell horrendously fishy. I can’t believe that anything that smells this bad, could possibly be good for one.

  • Richard

    I have a problem with Metformin smelling like fish but I don’t think the smell is what is causing my severe nausea and severe intestinal problems. For the last 180 days I had no problem. Before that the metformin and Starlex both smelled like fish. I had problems.

    My last 2 refills, 90 day each, had no smell and I didn’t have any problems.

    This last batch both smell bad and I have severe nausea and severe diarrhea. I don’t see how the smell could cause my severe intestinal problems.

  • Anne

    I have not noticed the smell of the pills themselves, but have been absolutely going crazy over the disgusting odor of my urine. It dawned on me today it may be the Metformin HCL.
    I’m definately going to ask my doctor to check for an alternative medicine. Are others of you experiencing foul smelling urine?

  • kitty knoll-aldrich

    Yes, me too. I’m now wondering if my slight feeling of nausea is from metformin.Im going to ask my doctor about changing formulas. I’d li k en to like to enjoy the food (taste, etc) and also smell good again. I have to scrub myself with soap use baking soda on my skin to rid the oily smell. And it still comes back in a few hours!

  • Kurt Alan

    Doctors are not gods, they make mistakes, too. Do the researchers offering the advice to stay on the drug take the drug metformin? I am too, thinking about stop taking this medicine. Been on it awhile. What is new as to my meds? Metformin 500mg twice daily. Will be cutting it back to half a dose. Wonder if cutting back on my carbohydrate intake will help the smell and the occasional diarrhea? Since taking metformin I have noticed eating sugary foods now has a dissatisfying taste sometimes. I need to do more research concerning this topic.

  • Kurt Alan

    Reading down through the list of posted comments I have to wonder if differences in different people’s metabolisms accounts for varying outcomes as to odor, nausea and diarrhea. Interesting to see that one person gets better sugar numbers with the more fishy smell generic form of metformin from his hypothetical experimenting.

  • TeresaClyne

    I am newly diagnosed with a pre-diabetes condition and was prescribed Metformin. I too noticed an overpoweringly fishy odor within a few days of starting the prescription. My nose and tastebuds are extremely sensitive to smell and taste, so this medication is something I have to forego. I see that someone else that posted on here is having good luck with diet. I will see how that goes instead of pills.

  • Leonard Raygor

    I have been taking Metformin for nearly 15 years. About 5 years ago, my pills went from a nice aromatic perfume smell, to dead fish. I complained to the pharmacist. He said he couldn’t do anything. I switched pharmacies. After doing some I-net research, I found a web site that listed all the names of all medicines along with the country of manufacturing. My smelly pills came from India. My nice pills came from the US and / or Canada. I instructed my new pharmacist not to give me pills made outside the US, Canada or the U.K. I also did the same with a nerve pill I take and noticed much better results with both pills. My diabetic meter numbers went down 10 on average. I suspect the quality of drugs from other countries might be lacking. I’m sorry to say, I did not keep the link to the page of the countries and have been searching for months to find it.

  • Karen Lower

    I have been taking Metformin for over 10 years. My type 11 diabetes is well under control. Recently I noticed that there was a smell coming from me that was unpleasant. My husband described it as sour, I called it more like acrid BO. I tried showering twice a day, switching to a clinical deodorant and a deodorant soap. Still the odor persisted. My bedroom and closet began to smell very bad. I removed the clothes hamper from my room and did laundry, including my bath towel, daily. At first the Doctor decided to reduce the amount of Metformin. When that did not stop the problem, the doctor said to go off Metformin for three weeks and check back. I am now in that 3 week time frame. The smell has abated from me, but now I need help in removing the smell from my bedroom and closet. I have laundered all the bedding, including mattress pad and blanket. I have used candles and boiled vinegar and let the fumes rise in my closed door closet. We had the carpets cleaned and replaced our air filters. I have not begun the daunting task of laundering or dry cleaning everything in our walk in closet. I surely would appreciate a way of ridding my home from this chemical smell. My pharmacist informs me that metformin is now made with a blackberry flavor because so many people have complained about the odor of the medicine. Does anyone out there have a suggestion? I am desperate!

  • Guillermo Corbarte’

    Recently started 2nd 90 day script of metformin. The 1st 90 day supply came in 2 bottles. Didn’t have fishy order. 2nd script of 90 came in one bottle. Fishy odor detected. Type diabetes is currently at goal.

    Good info on the fishy odor.

  • Sandra

    I have been taking Metformin for more than a decade without the foul smell I’m currently experiencing.
    Recently I switched pharmacies ( insurance reasons) for refills of Metformin, that’s when I started smelling the foul odor each time I opened the bottle. The odor was so horrific, I even considered stop taking the medication.
    I checked with the new pharmacy about the prescription Metformin and was told it was customary for this medication to have a fishy odor. I proceeded to explain that at the past pharmacy the Metformin didn’t have the foul odor. It’s such a terrible odor, I no longer want to take it.
    I plan to speak with my Endocrinologist about changing my medication and returning to my original pharmacy.

    • Stephanie

      I agree I’m doing the same

  • ruben salas

    I have no problem with the smell of the pill or urine, my problem is the almost painful feeling in my stomach! What would happen is i stoped taking metformina 850 mg.? Is there a home remady?

  • Ponyblanket

    I take this med myself; I smell the odor in “cheaper” versions.

    I had to learn: what makes Metformin?

    I found the chemical pathway is:

    TRIMETHYLAMINE is a colorless gas with a fishlike odor at low concentrations changing to ammonia-like odor at higher concentrations. Sound familiar?
    The pill ingredient HYPROMELLOSES helps in extended release. Think of it as glue around pieces of Metformin in a pill.
    So Hypromelloses gives extended release and seals in the “odor.”

    “Fill in the blanks” on why some pills stink more than others.

  • daughter_of

    My Doc didn’t put me on Metformin - until at least four A1C tests came back high (over 6.0 is boderline by her standards over 7.0 is a diabetic). I had been losing weight successfully prior so she was hopeful that I could get it under control by diet alone which I had I started at 6.6. Each of my A1C kept coming in lower then the previous so she was hesitate to medicate me. However, I went through a very tough time last summer (illness which resulted in the use of steroids which recks havoc on your blood sugar and unexpected death in family) and during this period I completely went off plan for about 3 months and my A1C was tested during that time. When my A1C shot back up to 6.6 again from my previous 6.1, my pcp decided it was time for meds. Since going on the meds and being back full force on low carb, I have lowered it to 6.0. She wants me to be under 6.0 for at least 2 tests (they are taken every 3 months) before she will stop the meds so I am close to being off the meds and when I am finally off them it probably will have only taken me about 9 months to get it under control.

    Metformin can be a very hard drug for your body to get used to taking. I have a delayed reaction to it in that I can take it for about 2 weeks before symptoms start (horrible diarrhea and painful gas) so I stop for about 3 days and then I start again and go another 2 weeks taking it. At first I tried suffering through it as my doctor instructed but due to my work schedule I just couldn’t handle it after 3 days of feeling ill and being tied to the bathroom. My doctor isn’t happy that I have to take it like this (and I am only on 500MG extended release) but she feels that being able to use it 90% of the time is better then never and my insurance won’t cover a different version.

    I did lose 8 pounds the first month without really trying but I think it was because of the side effects not real fat losses. I kind of maintained for about 2 months after that and then I started losing again. I have lost around 18pounds since I started it in January. I think it will all depend on how well your body can handle the medicine as to how you will lose weight on it.

  • Glenda Whittington

    I agree with the comment made about having a 3 month supply of Metformin that it could go bad – especially in summer or heat? Or just get old? I use the generic form and not have any problems with it other than some side effects which I deal with. I keep my meds in a cool place – could anyone tell me where the pills are made for the U.S.? I am told China. To me, I smell a very chemical smell more than anything else.

    • Donna

      The odor I get is a lead one. Ike when you sharpen your pencil

  • andrea

    Yes I agree with all the comments metformin reeks of a fishy odor. I had to let my whole entire family smell the bottle of pills one day everyone agreed even my urine smells so fishy I am so embarrassed go to the restroom in public I just put two . And two together that this is where the . Odor downtown is coming from I tried everything from douching to cleaning there three times a day it comes right back my doctor is the type who thinks everything is all in my head I think my head is telling me to go find a new doctor someone who will listen to me thanks for any suggestions or comments that anyone would like to say to help me please.

    • I agree with your plan for a new doctor, you would be better off with someone who could hear, as well as listen to you. Doctor reviews are more plentiful than before, and lessen some of my trepidations each time I have to change them out. Why can’t we have a single payer system and stop all the dinking around? Oh, that’s a different thread…lol.

  • Rebecca Gentry

    I have saved those little silica packets that come in some things, and put one in each new Rx bottle of metformin. I have found that this stops – or absorbs – the smell!

  • Joe

    I just leave the lid off of it, after a few days the smell goes away.

  • icesailor

    I never smelled any odor from Metformin and I’ve taken it for many years. Probably 10 years.
    The last prescription I got from Costco, the pills weren’t round, but oval shaped, and stunk like fish. I’m told that it is “normal” for Metformin to stink.
    I also think that Metformin is useless for me because no matter what I do, take it or not, it has absolutely no effect on my blood glucose levels. Glipizide will effect it, but Metforman won’t.

    • Stephanie

      I agree what’s up with the smell now and not before

  • tim

    after taking this drug for many years I got a bottle that smelled very bad, The next bottle was not so strong. My sugar levels did go up with the smelly batch.

  • I’ve been taking metformin for about four years and never noticed a smell until my current bottle. Fortunately it’s almost done; I detest fish and really hope the next bottle (from a different pharm) doesn’t reek.

  • Hans de Haan

    Yes, I have been using Metformine for 3 months now and definitely have bad smelling urine and faeces. I’ll ask the doctor for slow release.

    • Cathie Anderson

      I have been on metformin for two months and just noticed the bad smell in the last few days I also have a question for the past month the smell of raw meat makes me ill I cannot eat meat now. I never had this problem before I started metformin. My dr. says it has nothing to do with the metformin and dropped the subject he also said the bottle does not smell when I asked him to smell it he turned his back on me again.

      • B. Sharon Sarbin

        Cathie Anderson-if possible, switch Drs. ! Hopefully, you already have-this one is not doing you any good, according to the behavior you describe. Some doctors, when faced with a situation which they don’t recognize or understand, will ignore the patient, poo-pooing the patient’s concerns, state that there’s nothing wrong, instead of admitting they don’t know what the problem is or how to treat it. I have had many years of experience with many drs. with different personalities. Many are wonderful, some are average, some should be in another profession altogether. By the way, a pharmacist has 12 years of training. A general MD may have as little as 4-6. When you want to know about medicine, the pharmacist almost always has more information/experience. One literally saved my life when I was actually dying from a reaction to a medication I was taking post-op. The surgeon sent a prescription for phenobarbital and said it didn’t have anything to do with the surgery. I was so sick I couldn’t get out of bed by myself. I called my pharmacist, who began asking me many questions. Finally, he said to absolutely not take another pill, that I was experiencing a “text book allergic reaction” to the medicine, and the only symptom I didn’t yet have was to stop breathing. In 12 hours I felt much better and after 24 hours of stopping the drug, I felt normal. The odd thing is that I had had this drug before with no problem, but the surgeon had quadrupled the dosage this time ! Again, I’m not “down” on drs.-some have done some wonderful things for me and I am truly grateful ! By the way, I have been taking metformin for more than 10 years-have had some of the symptoms others have described, and noticed that sometimes it smelled fishy and sometimes not, and it was coming from different suppliers-Aurobindo being one of them. I was on 1,000mg. daily until I had a triple bypass almost 2 years ago, and suddenly needed only 250 mg. daily. Everyone has their own body chemistry to deal with, and it changes from time. I wish you-and all of us-well ! Good luck 🙂

  • Edna Scott

    I’ve taken the Metformin for over 2 years now and just got a bottle of some huge round pills that stink of urine and dead fish! It’s horrible! I’m holding my nose to take it and when I finish I’m definitely asking to go back to the other formulation!

    • Stephanie

      Me to

  • Cathie Anderson

    any one else on metformin notice that meat sea food foul tastes and smell bad. I almost vomit around meat now

    • Christina Garcia

      I heard extended release is better for the people who are sensitive to smells

    • Annie Rae

      Yes, I actually get almost sick just thinking about trying to eat meat most days. Chicken seems to be OK, but my taste buds changed completely. Things I used to love, like bacon? Can’t eat it now. That is not necessarily a bad thing, but I am pretty tired of chicken.

  • Stephanie

    I have been taking metformin for a couple of years and this last refill smells so bad I thought that the pills are bad. Why now and not before? I want to switch can’t stand the smell.

  • Suzanne Moore

    Yes, I have noticed the “fishy” smell lately, not when I first started taking the drug about 6 months ago, but definitely within the last couple of months….wonder why that is??

  • Alexis Lewis

    Yes, I was on Metformin and not only did it have a fishy smell, but it caused my body to smell like fish. People actually turned their nose up at me and gave me dirty looks because I smelled. I stopped taking it.

    • Annie Rae

      Happened to me too, I switched to extended release and that helped A LOT !!

  • Trish Hennecy

    It smells God awful and so does ones poop. I am at the point of getting a port a potty for my hubby because the odor is so horrific !!!!! There has to be a solution for this!! Come on this isn’t the dark ages people!!

    • Annie Rae

      My first doctor told me this was all in my mind, I’m glad to know “I’M” not the crazy one.

    • Peggy Bryant

      Same thing with my husband and all to often diarrhea,I can also smell it through his breath not everyday but a lot of days .ive come to think on those days maybe he’s drink less water to flush his system ? Who knows I just worry about him offending his friends from the smell since my husband is a very out going person never meets a stranger

  • Kathy Razinha

    I had been on metformin for years without any distinct odor until I picked up a refill. I called the pharmacy and they said they changed their supply company. I went to the pharmacy at my employ and they ordered from the previous company, NO fishy odor. After nearly 3 years, I was notified my employer could not justify the special order for just one employee. I then tried the pills again. I would vomit with every dose. Finally, I had a chemist friend analyze the pills. They found a component of fish oil. Low and behold, The reason I was sick was NOT side effects, but my allergy to fish!!! My MD discontinued immediately. When one of my previous pharmacies checked on it, they were told no fish oil used. However, when they checked as a consumer, not as a pharmacy they were advised yes, there is a small amount. There must be a brand of metformin that is NOT smelly, or include fish oil. I just found out that I have to go back on the medication. I Am Not a diabetic. I have another health issue that the FDA only approves metformin as a treatment for the metabolic problems. I am looking for an alternate metformin. If anyone knows of a brand let me know.

    • Tina Hague

      Was the manufacturer of your Metformin, Aurobindo, by any chance?

    • Nancy Wagner Johnstone

      I’ve been using Glumetza for about 8 years. It’s expensive, and it’s time release.

  • Tina Hague

    I have been taking Metformin for years with NO notice of any odor. When I received my very first prescriptions from Expresscripts, I noticed a HORRIBLE odor from the Metformin! It smelled like urine or dead fish. It was the first time I had received Metformin from a foreign manufacturer, Aurobindo. I also had an allergic reaction, and have found the medication to be suddenly ineffective! I no longer want to receive any medication manufactured outside the USA. We have NO idea of the quality control or extra ingredients from foreign companies!

  • sunjune

    The urine odor comes from the medication in it’s container. Once out of the container, the odor is not noticeable. I simply take the meds and try to convince myself that it’s not urine that I smell.

  • Dee

    The odor isn’t just when opening the bottle. I smell fishy smells at odd times. My urine smells fishy, probably my sweat, too. It’s gross. I haven’t stopped taking the med but it’s no fun. The nausea is not from the smell. I didn’t smell it at a lower dose and was still nauseous.

  • Lynne Mallya

    Mail order pharmacy switched to Aurobindo – never noticed odor until the switch. Also seems to not control blood sugar as well.

  • Lisa Everson

    Thank you. I thought I was crazy thinking my pills smelled like fish. I took it to a nurse at Kaiser who told me she couldn’t smell it. I’m a vegetarian and if there is fish in the formulation of the pills I will stop taking them. Definitely calling my doctor tomorrow.

  • Kimberly Ann

    makes my pee stink too

    • Annie Rae

      Oh Lordy, does it ever! Mine too! I tried to talk to my doctor about it and she said it was all in my mind. Changed doctors, changed to extended release and this got better – not completely gone – but better.

    • Millie Elmandorf

      mine too. smells like the pills in the bottle. never noticed this until mail order pharmacy changed the manufacturer to Heritage . my insurance wont pay for the extended release. and also I can NOT understand how they can justify the cost of the ER pills . I pay $8.00copay for the pills I take now. when DR tried to put me on the extended release tabs, the cost jumped up to over $700 per month. I am 70 Yo on medicare and certainly cannot afford that.

  • Mark Kelly

    use the timed release version, much easier to cope with, also i put mine in the frig, this seems to help as well.

    • Annie Rae

      I also started this, in an airtight container so the odor doesn’t affect the food.

  • waterflaws

    To call it a “scent” is too commercially correct – it STINKS. It reminds me of foul stagnant water,or my dog’s scent glands when they go off. The article doesn’t state WHY it smells. I assume that it’s made using genetically modified algae? I still take it, though, and only uncap it when taking it out of the bottle.

  • Anthony Brown

    I’ve read several of these articles. None describes what causes this unpleasant odor. Something “fishy” about that.

  • PMN

    My dad takes this and has a really unpleasant odor. I’m just wondering if there is anything to help.

  • Nancy Wagner Johnstone

    One brand of generic metformin smells horrible; I associated it with sewer gas (methane). I had to quit taking it when it started giving me diarrhea (after a few years of taking it), and my dr. helped me try several other forms of metformin. The one I could tolerate is Glumetza, and it is extended release, and many times more expensive that generic. In 2017, at least 2 of the huge drug insurance plans will not cover Glumetza.

  • Annie Rae

    Not only did I notice the sickening odor of the pills, my body chemistry changed when I started taking Metformin and I started battling with all sorts of odors that were very distressing. Switching to extended released helped both the odor of the tablets and the body odors they produced. It didn’t stop the odors, but it helped.

  • linda6521

    I asked my pharmacist about the odor, thinking maybe something was wrong with the pills. He reassured me that the smell came part and parcel with metformen. I just ignore the smell now. It does make my urine smell a little stronger as well. But what it does for my BG numbers is worth it.

  • g rosario

    I have not noticed any fishy smell, however, since all the pills are together in a small bottle yes there will be a slight smell. What I have noticed is that metforman really dosen’t do any big deal for your type 2 diabetic condition. I have been taking it for more then 5 years, my sugar was always at 200 or 247, even taking Gipiside with it, it wasn’t till I took Envokana with it, then I saw 89 and 105 readings, I trusted Metforman with all my heart, but why does it not work as well as Envokana. I eat the same, exercise, watch my sugar intake. can you answer that for me.

  • Al Cicere

    I take Metformin, and noticed the “fishy smell” upon opening the bottle. I do not notice it when It has been in my medicine box that holds all of my daily medication. I take it without fail, though. I figure it is just a nuisance. I am glad that I am not the only one that smells the odor.

  • Judy Meincke

    Interesting. I have a friend who complained about the awful smell of metformin and I thought she was crazy because I don’t detect any odor from it but I take the extended release formula.

  • Peggy Bryant

    I to can tell the medicine by the smell it’s not just taking it the bad breath it causes . it smells just like the meds .its not for a short time bc sometimes when my husband comes home from work I can still smell it .im always telling him please be careful not to stand close to people when your talking to them .my husband is a very out going person with lots of friends I worry about his friends being offended by this awful smell when I can smell it from eight feet away I’m sure everyone else smells it .signed concerned from Tennessee

  • Grace Gladney

    I have been taking it for quite some time now. When I first started, the pills were smaller and did not have an odor. Then about 2 years ago they switched me to a bigger pill which had the odor. Now recently with my last refill, I am back to the smaller pill which does not have the odor. This is strange as I am using the same pharmacy and dosage has not changed, but I am happy with the change.

    • Chuck Dixon

      It’s probably a change in the manufacturer. I know the pharmacy I use, They have changed brands a few times and the smell goes away too.

  • frank milton lipsky

    The lack of comment/notice by manufacturer of metformin’s odor is a disgrace .I have been using it for about 5 years but noticed the odor when I open the container has become more prominent in the last few year .Coincidently my wife complained that my body had the same fishy smell even after I showered
    This lack or label warning looks like a case for class action for the needless embarassment this drug has caused
    (Incidently my family physician stated he had no knowledge of other cases !)Furthermore why has diabetic asociation not demanded a Chromatogrpahic Gas analysis to identify the chemical components of the gas)
    Any scientists around know this problem is not rocket science.

    As a retired physicist this neglect is beyond belief
    computers are not substitutes for human analysis
    How can we say we have the greatest medical system in the world when stupid thing like metformin odors are ignored

  • Joel Morrow

    I had been taking Metformin ER, manufactured by Ascend. My pharmacy switched manufactures on my last 2 refills. With the Ascend, I didn’t really notice any smell. The the new manufacturer, Tagi Pharma, however…that’s another story! It had a strong nasty fishy odor…or like the inside of the innertube of a freshly blown tire! But!…Getting past the smell wasn’t the worst part! I noticed that my sugar numbers had risen substantially! At first I thought it must have just been me…something I may have been doing different. I did a little SPC on my levels over the past 3 months of Ascend brand and 1 month of Tagi! I noticed that I had a lot of number running in the 130’s and 140’s. So as a control, I picked numbers greater than 119. The previous 3 months were pretty consistant, with the last month actually down 15%! That was a good thing! But! Then…the day after I started the Tagi branded product, my levels went from 110…112 to 133! And it proceded to get worse! I calculated a 77% increase in numbers greater than 119! Numbers 130 and Higher, up 300%! After this last (second) refill of the Tagi brand, my numbers continue to be in the 130’s and 140’s! I think this is statistically significant enough to say with pretty much certainty, that not all metformin is created equal! I complained to my pharmacy and they said they would “try” to get the old brand for me..but! No guarantee! Well?!…I am going to tell them that they eithewr get me my old Ascend brand Metformin ER or else!..or else I will take my perscriptions elsewhere, where they are more accomodating…and I WILL give them a “GUARANTEE” with that one! 🙂

  • Diane Holmes

    The stuff smells like rotting fish!

  • Jeanne

    I have found that if you put one of those little preservative packets in the bottle, it absorbs the smell. Try it and see 🙂 It worked for me, and there is no one who hates fish smell more than I do.

    • Gail Ciesielski

      Wow! Really?! I’ll try that! Thanks!

  • Rosemary Limon-Saucedo

    To me it smells like urine…checked with the pharmascist to find out where it was produced, not all metformin is produced in one country ugly…sometimes my urine smell like metformin…yuck…

    • Gail Ciesielski

      Rosemary, that is what I think it smells like! Yuk! I’ve been trying to find out just WHAT Metformin is made from. I have not yet found that out. 🙁

  • Rosemary Limon-Saucedo

    WOW, thought it was just me smelling, unfortunately the insurance/medicare wont let you have other than generic when your over 80…and even before….I’ve been taking metformin since 1991, that;s 26 years…earlier in years, it never smelled, seems like the past five-six years, whew, stinko, urine city and makes my urine stink too. .

  • Subh

    I just figured out that the smell can be present or absent based on what manufacturer has made it. This one has the smell, while this one does not, although both are Metformin Hcl ER. My pharmacist gave me two bottles, one of each type. That’s how I figured this out.

  • Alfred Hopkins

    Ask the pharmacist do this medication smell fishing she said no but it did this 500 milligrams of Metformin stinks apple cider vinegar I take.

  • Lois Laine

    Metformin manufactured by Sandoz smelled like rotten fish. Within a month of taking it I got acid reflux, which I have only had once in my life with my first pregnancy 3 decades ago; my sugars became elevated and uncontrolled due to what I feel was poor absorption; and I contracted a yeast infection which, again, I haven’t had but once before in my life 3 decades ago. I switched to Metformin by PMS and have had to go back on insulin to get my sugars back under control.

  • Laurie Owen

    I noticed the smell, I just leave the caps off and it airs the container out and I dont notice the smell after that, I don’t put the cap back on either, if you do, the smell comes back.

  • Mike Polz

    Are you still using Ascend? Have you lost weight on it? I’ve just started taking it this week. I had been on the teva and heritage versions but I didn’t notice much.

  • Jay Cheramie

    Ever since I was diagnosed with Type2 diabetes and started taking Metformin, my groins have been smelling fishy and it is very embarrassing. I have used apple cider vinegar to cleanse the area but then I smell like vinegar !!!