Controlling the Dawn Phenomenon

Do you wake up with a blood glucose level that’s higher than when you went to bed? You might wonder how this could be. Is this “dawn phenomenon” serious, and what can you do about it?

Our reader Mishelle commented here, “I don’t eat [much] during the day. [I take metformin morning and night.] My blood sugar is still too high in the morning…sometimes 125–140ish.”


How can Mishelle’s glucose levels go up if she didn’t eat anything? She probably has a mild case of dawn phenomenon. Her glucose is going up from sources other than digested food. Some of it is produced by the liver from stored starch and fatty acids. Livers that produce too much glucose are one of the main ways diabetes causes high blood glucose levels. Other organs also produce small amounts of glucose. This is called “gluconeogenesis” for you science freaks out there.

Organs do this to keep blood glucose from going too low at night or other times of not eating. From about 2 AM to 8 AM, most people’s bodies produce hormones, including cortisol, glucagon, and epinephrine. All these hormones increase insulin resistance and tell the liver to make more glucose. The idea is to get you enough glucose to get out of bed and start the day. The whole process is apparently started by growth hormones.

Everyone has a dawn phenomenon. Otherwise they’d be too weak to get breakfast. But in people without diabetes, insulin levels also increase to handle the extra glucose. People with diabetes can’t increase insulin levels that much, so their early morning blood glucose levels can rise dramatically.

Experts disagree on how many people have a dawn phenomenon. Estimates range from 3% to 50% of Type 2s and from 25% to 50% of Type 1s.

Is dawn phenomenon a serious problem?
It can be serious. According to the American Diabetes Association, “Some people with dawn phenomenon find that their glucose continues to rise until they eat in the morning. For others, levels will settle down a few hours after waking, regardless of whether or not they eat.”

Either way, that can be a long time to spend with elevated blood glucose levels. For some people, like Mishelle, the highs aren’t that dangerous. Others go much higher.

According to columnist Wil Dubois, the higher your A1C, the more likely you are to have a significant dawn phenomenon. It could be that spending a number of hours each morning out of control is having a significant effect on your overall control.

So it’s worth trying to get dawn phenomenon under control. How can you do that? You have to figure out what is triggering it and then try some possible solutions.

Some people have high glucose levels in the morning because their medicines wear off overnight. This could be true of medicines like insulin, sulfonylureas, and metformin. If you are taking any long-acting medicine, consider asking your doctor about changing meds, doses, or times. Our reader Mishelle might benefit from taking her metformin later in the evening, for example. Metformin is good at keeping a lid on the liver.

In some cases, medicine can be too strong. If your glucose goes too low in the night, you could have a rebound high in the morning. This is called the Somogyi effect. Wil Dubois says

If you are waking up high and are suffering pounding headaches, or find your sheets sweat-soaked, the odds are you are having lows in your sleep…You need to visit with your doctor about taking less meds.

According to Dubois, the new insulins are much less likely to cause a Somogyi reaction. But because of cost, people are going back to NPH insulin. NPH is cheaper, shorter-acting, and more likely to cause a low, leading to a rebound high in the morning.

What can you do to reduce or eliminate dawn phenomenon? Diabetes blogger David Mendosa says many things work for some people and not for others. People report blocking the dawn phenomenon with a green apple or a cornstarch product — here’s one Mendosa mentions — at bedtime. These might keep a low, steady, level of glucose coming and might prevent nighttime lows and highs.

Not eating at all after 7 PM probably won’t help. It will set you up for a Somogyi rebound. A protein snack like nuts or cheese at bedtime might help. But you will have to experiment and keep records for yourself. Everybody is different.

Mayo Clinic doctor Maria Collazo-Clavell, MD, says avoid carbs at bedtime. She also says an insulin pump can help a lot. You can program it in advance to increase your insulin when the dawn phenomenon starts to kick in. You might have to check a few middle-of-the-night levels to find out when the phenomenon starts for you, or if you are going too low.

Alcohol at bedtime is another choice. A glass or two of wine or spirits might keep your liver too busy to bother pumping out extra glucose in the morning. Alcohol also helps some people get to sleep.

Unfortunately, alcohol often wakes you up again way too soon. And there is a risk of going low AFTER breakfast if you drank the night before. (Editor’s note: Because of these, and other, risks of alcohol, it is not recommended that you begin drinking just to combat the dawn phenomenon.)

Vinegar might be the best choice. You can take tablets or a liquid. Most people I’ve read commenting on various sites needed 4–6 vinegar tablets at bedtime to avoid a morning spike. There’s not much research, though vinegar has been shown to reduce insulin resistance.

Hope this helps, Mishelle. Readers, do you have other ideas? What have been your experiences with dawn phenomenon?

  • jim snell

    excellent comprehensive article and covering many aspects of Dawn Phen. Thank you.

  • Bob Fenton

    Thanks for this. Why I have to be an exception to what this article states “The one medication that does prevent this is insulin.” is still puzzling for me. Until I split my dose of Lantus, I would have continued problems with the dawn phenomenon. Shortly after splitting my dose, I no longer had this problem.

    Thanks again!

  • Ms Mercer Ervin

    I didn’t know 125 blood sugar in AM was too high?

  • David Spero RN

    Ms. Ervin,

    A fasting sugar of 125 mg/dl is prediabetic. Mishelle wants hers to be lower, and lower is better. But its her choice and your choice what goals to shoot for.

  • Joe

    I’m interested in what Bob had to say about splitting his insulin dose. I’ve heard people who take larger doses of Lantus (or other long-acting insulin) getting better results splitting it into two doses, 12 hours apart.

    I’m up to 50 units of Lantus and am curious about the pros and cons of two 25 unit doses vs. on 50 unit dose.

    Perhaps an idea for an article or blog entry?

  • Pat Kass

    I have experiennced higher than expected/accounted for readings on awakening aftter a “busy” nightmare. One in particular was a dream that I was filing things and was like the sweeper in Sorcerer’s Apporentice cThe more I filed — the more there was to be filed. (I have been retired from office work for 20 plus years!)

  • Mr. Gregg

    I have had the “Dawn Phenomenon” for years. My diabetes specialist could not add or auggest any solutions, so I took it upon myself to split my Lantus dosage to 50% in the morning and 50% at bedtime. I now wake up with a much improved glucose reading but, on occasion, it is off the charts! I cannot figure out why….In addition, I sometime wake up in the middle of the night to go to the bathroom and my tee shirt is wet. I suppose my glucose went too low but it did not waken me. I have had Diabetes since 1991 and I am still learning each day about the struggles to maintain an acceptable level reading.

  • Terri

    If I did have that problem, my doctor wouldn’t believe me. She’d just accuse me of carb loading or something…a split of Lantus does seem to be effective though.

  • jim snell

    As a 30 year type 2 and having dealt with an extremely nasty dawn effect and liver dumping problems of my body and with my Doctor’s assistance and watching extensive data on a cgms; I have the following comments:

    a) at 3:00 am, my body starts the wakeup sequence and starts signalling the liver to add glucose.

    b) liver uses reverse signaling based on the presence of insulin in blood to control how much glucose to add and when to stop doing that. So if you are short insulin, oh boy, look out liver assumes you are short glucose and really loads up body – never mind you don’t need much or any glucose.

    c) I have watched comments from the pumper crowd and those instructed to add extra insulin and if their liver is listening to signalling properly; adding basil insulin or extra insulin during these times; liver is determined to hammer up glucose seems to stop, moderate, arrest that.

    d) for those of us -, I believe who have compromised liver signalling ( and assumed due to extra fat inside liver (not belly/body fat), metformin was the only option that at sufficient dose in blood arrests that nonsense and instructs the liver to stop dumping in excess glucose.

    I also found that metformin was very helpful for stalling out rare but curious unnecessary liver dumps at normal times.

    e)after a number of years of restricted diet, low carb 1200 cal diet, 1.5 mile daily exercise and regular metformin doses; I have discovered that my liver is listening better to body insulin and does of insulin late at night and that now also helps keep blood glucose thru night under better control. The beauty of the pumps is that one can instruct the computer when to add insulin and how much and fine tune the liver’s behavior.

    f) adding snacks late at night , I do not due but suspect that eating triggers a bolus add of insulin from a working/partly working pancreas to add insulin and that helps arrest liver tricks/misfire.

    It has taken the last 5 years to walk, try, experiment and finally arrest this nasty dawn phen which frankly is one nasty customer.

    David: Special thanks for shining a light and key column on this nasty problem that underscores the role of the liver and its buffer and horsepower to sugar up the body!

  • Ferne

    For those of us who have the horrid side effects from Metformin, taking it later without a meal would make those effects worse. I have to have a snack with my HS meds but haven’t figured out the best one.

    • Jane

      Metformin must never be taken on an empty stomach. Always take it with some sort of food.

  • RUTH A

    I too was having high numbers in the A.M… 125-135 and sometimes 140.. I read about Vinegar in an article in “Diabetes Management”, about Vinegar , So I tried it, You will not believe how great it is! now you have to be careful if you take too much you will really lose weight, being a thin person, this was somethng I didn’t want to happen,, but I over came my fear and being who I am, I conquered it.My numbers went from 138 , 140 to believe this or not,, to 125,121,111,100,, and so forth. I am smart enough to realize as I was watching these numbers when to cut back on the vinegar..but not stopping it altogether,, My A1C’s went from 6.8 to a glorified 6.5.. Now it takes some getting used to the vinegar, I used White Vinegar as the Apple Cider made me shutter.. Just take 1 tables spoon of Vinegar in 1/2 glass of water, take it after you have eaten, but not at the same time as you take your pills. And see what happens..
    Good Luck,

  • Donna G

    I am allergic to Metformin and choose to regulate blood sugar at this point with lifestyle changes of diet, exercise, weight loss, stress reduction and supplements. Dawn phenomena remains my only consistent blood sugar issue. Through personal research, I have tried all of the suggestions noted in the excellent article. There were very little information out there when I first tackled my DP. Vinegar did not work for me, but better sleep habits, lowering stress, meditation and nighttime snacks have lowered my morning spike to a point I no longer worry about it. This was a long process of testing what worked for me, and lots of finger pricks, but worth the effort.

    Here’s what helped me without question:
    Do not eat a heavy evening meal.
    After dinner, I eat a small snack at 9PM (I usually eat string cheese with a few almonds or hummus with a high fiber cracker or sweet potato corn chips with guacamole. No more than six chips or three crackers. I think eating the combination of good fats and protein, or good carbs and protein work best for this evening snack)
    Eat another snack right before bed. I usually eat a medium sized apple (good carb)but have also had half of a low carb snack bar(also worked for me). I usually eat my apple with a sugar free nut butter spread (protein). It does not have to be a green apple, but I do choose tart varieties.
    If I wake in the night I drink water and eat 4-5 almonds or walnuts really taking my time to chew them to a paste. (to avoid digestive issues) The middle of the night nuts usually give me my lowest dawn readings. My blood sugar levels do best when I eat every five hours throughout the day, (3 light meals and three small snacks) so makes sense to me this would be best at night as well.)
    In addition–I try to be faithful in getting good sleep at regular hours, wear a Breathe Easy strip to get better levels of oxygen if I am at all stuffy and have an air filter fan running at night.

    Stress (a cortisol producer) usually makes the dawn number higher for me, so I meditate and have worked to de-stress my life. Exercise lowers my blood sugar, so I do weights and a rower. But never for more than half an hour. Muscles gets stressed when you exercise too long, and pump out more of the hormones that creates dawn phenomena.

    I also take vitamin and fiber supplements: a good multivitamin, extra D, extra C, Black current oil, CoQ10, cinnamon and turmeric

    I’ve lost 50 pounds. My fasting blood sugar reading was 350 on diabetes diagnosis day a year ago. My three month average was 10.5. It is now 6.4. (Doctors should know that a fasting blood sugar reading is always going to be higher for a patient with dawn phenomena, but they usually don’t factor that in.)
    My dawn phenomena readings have gone from average of 250 to 124. As overall blood sugar readings go down the dawn number goes down, too, so I have focused on getting the overall readings down. Good luck to all who are working to get dawn phenomena under control.

    • Janet

      Thank u so much for this specific information. I’ve been searching for awhile but this really makes sense. A few of the things my endocrinologist has mentioned…….cheese, high fiber crackers. I too have engaged recently in an exercise program and am following weight watchers diet. I appreciate the fact that u have taken the time to share this info.

    • Chris

      This really helped. I’m type 2, 66 yrs old and I’m experiencing high morning readings. I’ll do some adjusting with eating habits. Thank you for taking the time to inform all of us trying to stay healthy & active.

    • Jeanne

      Thank you so much for all of this wonderful information, Donna. I’m a recently-diagnosed T2 and I’ve managed to get my daytime and evening numbers down. But this gall-dern dawn phenomenon has me perplexed and concerned. It sounds like it’s going to mostly be a matter of experimentation to see what works to get this handled. But, you’ve given everyone a great jumping-off point and I – one among several – appreciate it.

    • Kristym

      good job!

  • Joanne

    Donna G – Glad I found this page. I am diagnosed just over a month and my morning readings can be 160-180. I am going to try the vinegar tonight as well as leaving some nuts by my bed as chances are good I will wake up at some time.

    Thank you – sure hope it helps

  • Joanne

    oh sorry it was Ruth with the vinegar :-) I will see what works for me!

  • Lenny

    Hi, from Greece, to everyone.
    It’s 20 days now since I left the hospital with a type 1 diagnosis.
    My readings before entering were 320 fast & 580 at about 9 pm.
    Now I do 3 fast acting inj. before meals and 1 long acting at 5 to 6 pm.
    Before bed I eat 2 small burley rusks, 1 low fat (2%) yogurt and 2 nuts, total 30 gr of carbons.
    My morning reading today was 111 mg/DL.
    I’ll inform you after a couple of weeks for how is going.
    Good to know you are all there.

  • lily

    I have diagnosed with diabetes 3 months ago my blood glucose was 570 and I have also diagnosed 6 years ago with hyperthyroidism I never loose weight on the contrary I am always gaining weight and I am always waking up have this spike of vlood sugar ( 140 to 180 )
    Please help and guide me what to do ro low my blood sugar and also loosing weight to get healthier

    • deepred

      Hi lily, i have been recently diagnosed with Diabetes Type 2 with levels of 371 on random basis, A1C of 8.2. But after one month with diet and excercises , metforming 1000mg was able to bring it down to range of 150. Now fasting glucose levels after wake up are in the range of 100-140 levels, it is actually coming down from 150 in first few weeks. Major improvements in fasting levels is because of daily walk 1 hr. Fasting BG levels is more to do with Hormone imbalance, (Haptic insulin resistance) this will take time to correct with changes in Diet /Excercise /Medication. I know none of my levels posted above are in good range, but they are getting better.Just want to give my opinion, that if you can try to include excercise (basic level) walking (MUST CHECK WITH DOCTOR before start of excercise, especially if you have high blood pressure, blurr vision, have sedentic lifestyle before) … it will help your BG levels. its worth every effort, i wish all the success to get BG level in control. Wish me luck too… bye.

  • Sharon

    Lily, tho my bg was not up as high as yours, and I am only on oral medication, I too had the same problem of fluctating bg levels and constant weight gain. My Dr told me about a book The Blood Sugar Solution 10 Day Detox by Dr Mark Hyman, there is also companion cookbook. Changing my diet completely seems to be what is helping me.

    • Chris

      I’ve been using Dr Hyman’s books on blood sugar and they work. I got lazy and everything started to back slide. I’m going back to his cook books to get back on track. I take metformin and a bunch of other Meds after heart attack. I don’t mean to hype dr Hyman but the change in diet made a huge difference. I’m 66 yrs, had a heart attack at 58. I’m losing weight and feel much better when I follow his suggestions. This is a great forum.

    • Kristym


  • Bill

    My theory is sleeping habits are to blame. Less sleep mean more hormones produced to wake a person in the morning. I have notice more of a problem when I have had issues sleeping the night before. Adjusting your insuling will help some but if you have a steady relese of the hormones telling your liver to release glucose then you can never know how much to take…

  • Charlotte

    I have low blood sugar, so I guess I’m what’s called, pre-diabetic. I am managing low blood sugar symptoms with low glycemic foods and eating almonds in between small meals. You mentioned cornstarch to prevent the dawn effect to be able to sleep through the night. Can you tell me a recipe for this? Would it be for example to blend a cup of soy milk which has protein with a teaspoon of raw cornstarch? Or what combo do you suggest? Thank you.

  • V. Richards

    My Doctor prescribed Invokana at night (100 mg). I currently take Glipizide XL (10 mg) during the day. The Invokana has helped reduce the morning readings from 140-170 to around 120. I have only been on the Invokana for five days and am wondering if anyone else has used this drug and what side effects that have had.
    V. Richards

  • esme

    i go to sleep with 162 at midnight it was 487 than at two am it was 234 than at seven am it was 206 i corrected every time i need help

  • Frank Nagy

    i have dawn phenomonon really bad. I am on Levemir and humalog, type 1, regardless of how much levemir i use no matter if i don’t eat before bed. I can be guaranteed to wake up between 135-160 no matter what. I thought NPH would help that, but that only caused morning hypos

  • birendra

    I am 35 years old. A month ago my FBS was 213. After two week it was 81 .after one month it was 89. Is it possible?

    • Natasha

      That’s fantastic. I would love to know exactly what you did and what all you changed

    • sacto1971

      OMG what did you do…please share and thanks

  • squawkparrot

    Hi everyone… I became a type 1 diabetic in 1990. In 2001 I took some graphs to my doctors to show him that my morning blood-sugars were rising, and wanted to know why. He took a three second look at the data, pushed the graphs back to me and said, “I don’t know”. That was that, I was on my own.

    Over the next couple of months, the rise, which was at first sporadic, became more certain, and so I was able, on waking, to give myself an injection of 25 units of fast acting insulin (actrapid) to counter the inevitable rise.

    In 2007 I managed get a hospital diabetes doctor to take another look. I told him that I only took Actrapid, no other type of insulin. He said that my morning phenomenon was probably due to not having any background insulin. So, to give me some he put me on Levemir, a 24 hour long lasting insulin, just like Frank, see below. But this was useless. I started off by injecting small amounts of Levemir, just 3 units to give me a little background insulin, but increased it to 30 units before bed each day, after two weeks I went back to the regime of waking and giving myself the 25 units of Actrapid.

    In 2013 I had another go at resolving this ongoing problem, and saw another doctor, then a nurse, then another nurse and she put me on Lantus Solostar, 12 units just before bed, and 12 units in the morning. This worked to a point, but I adjusted the dose myself to 26 units just before sleeping, and kept the 12 for the morning.

    The result is, that providing I go to bed with a stable reading of 8 on the meter, I wake up with a reading of approx 3-4 in the morning. And, more importantly, my blood-sugar does not rise, for apparently no reason later on, as long as I start with 12 units of the Solorstar.

    I used to have a number of severe hypos because, I was always attempting to counter the highs brought on by the morning phenomena to keep my blood-sugar levels as low as possible. But, even doing this, I was only achieving a HbA1c of around 7.5% in old money. Since the introduction of the Lantus Solostar regime, I have less hypo’s and, the severity of them is much better because, I’m not having to keep pushing my levels down to get the 7.5% average reading.

    My last few readings of the HbA1c have settled down to 6% in old money or, 41 mmol/mol in the new way of measuring. When I ask for a printout of the blood test result from the doctor (yes, you should be able to get them) it indicates that I am now considered to be a non-diabetic, at least by way of my average readings of blood-sugar. At last, after 25 years as a diabetic, my level of control is such that I will not have to suffer, as much anyway, the longterm effects of high blood-sugar levels. But, unfortunately, some damage has already been done because of this failure to address this problem.

    I hope, if people are still reading this blog, this posting is of some assistance?

  • FrozenTales

    I have had type II diabetes for the past 25 years. For the first decade or soI could control it with minor changes in diet (no sweets and tea without sugar) but have been under medication for the past 12 years. It started with metformin but later over a period my doctor had to add Amaryl (5mg a day), Januvia 100 and 12 units of lantus insulin. For the past couple of years I had also been trying to reduce my carb intake.

    However, for the past little over six weeks, I have been off food grains completely. With a week of quitting food grains, I have been off insulin as well as Amaryl. My post breakfast and post dinner glucose levels remain around 130. Unfortunately, it is in the same in the morning – even though during the night it goes down to about 120.

    Any suggestions?

    • David Spero RN

      Sounds like you are doing really well, Frozen. About your high fasting levels, you could try adjusting the timing of your meds. You could also take a tablespoon of vinegar or a vinegar capsule at bedtime before you brush your teeth. In a couple of studies, vinegar reduced fasting sugar levels by 30-40%,which would bring you into the normal range.

  • Madhall

    I too suffer for high morning readings. Yesterday morning it was 128 at 6am, an all time low. Today it was 218 at 6am and went down to 148 by 9am. I basically are the same thing the night before took the same meds and supplements with too different results. I am going to try green apples and vinegar tablets to see if it makes a difference.

    On another note, I went on Invokana a year a a half ago and my kidney function dropped to 51%. I found that unacceptable so I sought alternatives and found a chiropractor who specializes is diabetes management. I am now grain free (which includes glutins), dairy free, caffeine free, sugar free, and artificial sugar free (only Stevia, and xylitol). I was taking four different meds but now I only take Amyral at night. I have lost 32 pounds, feel great, and now have problems with low blood sugar in the mid afternoon. The lowest was 49 and that was when I stopped all morning meds. I do Pilates three times a week and that was when my sugar readings are the lowest, now between 67-90. I do take supplements for my adrenal glands, after a saliva test it showed they might be playing a role in my insulin resistance.

  • Larry Rotenberg

    Circadian……i got rid of my dawn phenomena by eating upon waking and a second big meal at lunch……keto…….no snacking and no dinner……

  • Larry Rotenberg

    No meds and bg went from 7 to 8 to 5 ….end of day 4.5……….

  • Dennis Poole

    I was diagnosed with elevated blood pressure four years ago and was placed on TWYNSTA 40/10. Since then my quality of life has been in turmoil, sugar levels are all over the place.Nausea, oedema in the lower legs sore throat and headaches. Tablets have been changed and some side effects have diminished but I had none of these problems before taking the tablets. Vinegar seems to be helping with the dawn sugar levels

  • joycebarron

    My husband has always liked pickle juice to drink and swore he felt better when he drank it. After a recent stroke we are working hard on his blood sugar levels and that is when we realized he has a strong dawn phenomenon. He hates pills and said no when I suggested the tablets so I tried the pickle juice at bedtime and it’s helping a lot. I give him a couple tablespoons from the jar. It’s basically vinegar with some spices and since our overall diet is so low in salt it’s not been making him retain water

  • Bork

    I tried it last night…a shot (60% abv), diluted with 1:4 water. 100 glucose instead of 300 in the morning.
    I’ll try it again tonight and see if the results repeat.

  • Rita L

    Thank you all, this is the most informative website I’ve found to date. I’ve been a T2 for 12 yrs, am 67 yr old F, was on 120 units Lantus for a number of yrs, finally got it down to 60 units by cutting carbs. Then in Jan this yr cut out all grains and high carbs, except beans, put myself on high a fiber diet, got down to 20 units Lantus, lost 20 lb. Now I’ve been trying to get into ketosis for 5 months. I make ketones just fine but have high BS ‘s in the am, 150-180, no matter what I eat or when, have tried just about everything, even exercise. Dr took me off glipizide, said it affects the heart, he thinks I’m on a bizarre diet. So now before I go to bed it’s down around 120 and it starts all over the next morning. Have tried wine, high starch, no help. Just started mulberry capsules. Tonight I’ll try vinegar, wish me luck!
    By the way Charles, I was up to the bathroom the other am at 4, BS was 87 so I stayed up, took metformin, had some protein with decaf coffee. BS kept going up till abt 9 am when it leveled out at 134. Just my experience, might work for you though, nothing seems to work for me.

  • Rita L

    OH! Forgot to mention I’ve been off Lantus for 4 months, 2 months ago my A1c was 5.9. I’m sure it will be around 135 or so, per my meter. Am on 850 mg metformin 3 x day plus various herbs only. Am going for diabetes free with controlled diet (Keto).

  • Arvindkumar Srivastava

    Is dawn phenomena linked with the lack of sleep or interrupted sleep pattern also? my bed time BS level is in 90s but fasting is around 110. I sleep late and had to get up sometimes in night. I take my night medicines metformin 1000 and Januvia 50 before meals around 9.30 PM.