How Much Do You Know About Concentrated Insulin?

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How Much Do You Know About Concentrated Insulin?

Today there are many different types of insulin on the market – some are long acting, some are fast acting, and some are in between! There are premixed insulins that combine a fast-acting and an intermediate- or long-acting insulin. There’s even an inhaled insulin! And there’s another type of insulin that you might not be as familiar with, called concentrated insulin. What is concentrated insulin, and is it something that might be right for you?

Insulin types

If you have type 1 diabetes, your pancreas makes little to no insulin, which means that you must take insulin for survival. Many people with type 2 diabetes or gestational diabetes (diabetes during pregnancy) take insulin, as well.

Insulin is injected using a syringe or a pen; it can also be infused with an insulin pump. One type of insulin, Afrezza, is an inhaled insulin.

Several types of insulin are available; each type starts to work at a different speed, known as “onset,” and its effects last a different length of time, known as “duration.” Most types of insulin reach a “peak,” which is when they work their hardest and have the strongest effect. After the insulin peaks, the effects of the insulin start to wear off.

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Insulin “strength”

Knowing the ins and outs of insulin can be a little confusing. But in order to understand what concentrated insulin is, it helps to have a refresher on what is called insulin “strength.”

Insulin comes suspended in a liquid. Most of the insulin sold in the United States is U-100, which means that there are 100 units of insulin in every milliliter of liquid. U-40 insulin has 40 units of insulin per milliliter of liquid. This type of insulin isn’t used as much anymore, but it’s possible that it’s available in some places outside of the U.S. (U-40 insulin is still used in veterinary care). The American Diabetes Association advises that if you are traveling outside of the U.S. and need to use U-40 insulin, you need to be certain to match the insulin strength to the correct size syringe. Never use a U-100 insulin with a U-40 syringe.

Insulin in the U.S. is available in strengths other than U-100. These include:

  • U-500
  • U-300
  • U-200

These insulins are best suited for people who require large doses of insulin in order to reduce the amount of insulin injected at any one time and reduce the number of injections needed.

U-500 insulin

U-500 regular insulin has been available since the 1950s. This insulin is a concentrated form of regular insulin (regular insulin is a short-acting insulin) and is approved for use in people with type 1 or type 2 diabetes. Each milliliter of U-500 insulin contains 500 units of insulin; this means that it’s five times more concentrated than U-100 insulin, making it a much more potent insulin.

Eli Lilly is the manufacturer of U-500 insulin, called Humulin R U-500. U-500 insulin is intended for people with diabetes who need very high doses of insulin — typically more than 200 units per day — to help manage their blood glucose levels. Usually, these are people who are very insulin resistant. It can be used on its own or in combination with rapid-acting insulin and oral diabetes medicines, as well. U-500 insulin is taken two or three times daily, 30 minutes before a meal, and it’s available in a vial (to be used with a U-500 insulin syringe), as well as a U-500 pen.

Although U-500 insulin is “regular” insulin, it works more like an intermediate-acting insulin, such as NPH insulin. For this reason, Patty Bonsignore, RN, CDCES, advises people who take U-500 insulin that they may need a mid-afternoon snack and possibly a bedtime snack, as well. She also states that it’s important to eat meals at consistent times to help avoid hypoglycemia, or low blood sugars. U-500 is usually given as a set dose, as well. For more information on U-500 insulin, visit the Humulin U-500 website.

U-300 insulin

U-300 insulin is insulin that contains 300 units of insulin in every milliliter of liquid. Currently, the only U-300 insulin available is insulin glargine U-300 (brand name Toujeo) and it’s only available as a pen. Insulin glargine U-300 is a basal, or long-acting, insulin that’s approved for use in adults with type 1 or type 2 diabetes and children ages 6 years and older with type 1 diabetes. This insulin may be a good choice for people who have frequent hypoglycemia or who have insulin resistance requiring larger doses of insulin.

Insulin glargine U-300 contains three times the amount of insulin per milliliter as insulin glargine U-100 (brand names Lantus, Basaglar, and Semglee). It’s injected once daily at the same time each day and may last up to 36 hours. Insulin glargine U-300 is not a mealtime insulin, so if you have type 1 diabetes, for example, you need to take a mealtime insulin, as well. This insulin is not interchangeable with insulin glargine U-100, as it is much more concentrated.

Toujeo insulin glargine U-300, manufactured by Sanofi, is available in two disposable pre-filled pens:

  • 1.5 ml Toujeo Solostar: 450 units of insulin per pen; delivers in 1-unit increments, up to 80 units per injection
  • 3 ml Toujeo Max Solostar: 900 units per pen; delivers in 2-unit increments, up to 160 units per injection. This form is recommended for people needing at least 20 units per day.

U-200 insulin

Currently, there are two forms of U-200 insulin: insulin lispro U-200 and insulin degludec U-200. Insulin lispro U-200 (brand name Humalog U-200) is a fast-acting insulin that is injected before meals. This insulin provides 200 unit of insulin per milliliter, which is two times as much insulin as insulin lispro U-100. This insulin may be prescribed for people with diabetes (adults and children) who require high doses of mealtime insulin.

The Humalog U-200 KwikPen, manufactured by Eli Lilly, holds twice as many units of insulin (600 units) as the Humalog U-100 KwikPen (300 units). As a result, the Humalog U-200 KwikPen lasts longer between pen changes. Also, this pen is dialed in one-unit increments to a maximum of 60 units of insulin per injection. For more information about Humalog U-200, visit the Humalog U-200 website.

The other type of U-200 insulin is insulin degludec U-200 (brand name Tresiba U-200). This is a long-acting insulin that is usually injected once a day and is approved for people with diabetes 1 year of age or older. (Of note, Tresiba also comes in a U-100 form). Because insulin degludec U-200 is a long-acting insulin, you may need to take mealtime insulin before your meals, especially if you have type 1 diabetes. Insulin degludec U-200 is twice as concentrated as insulin degludec U-100, making it beneficial for people requiring more than 80 units of insulin daily, which can’t be administered by a single injection with a U-100 insulin pen.

Insulin degludec U-200 is given once a day, preferably at the same time each day. Because of the formulation of this insulin, it may work for up to 42 hours a day. This insulin is available only in pen form as the Tresiba U-200 FlexTouch pen, manufactured by Novo Nordisk. The pen holds 600 units of insulin and delivers a maximum dose of 160 units of insulin per injection. For more information about Tresiba U-200, visit the Tresiba website.

Talk with your health care provider if you think a concentrated insulin may be right for you.

Want to learn more about insulin? Read “What Does Insulin Do,”  “Injecting Insulin: Tips for Success,” and “Insulin Basics.”

Amy Campbell, MS, RD, LDN, CDCES

Amy Campbell, MS, RD, LDN, CDCES

Amy Campbell, MS, RD, LDN, CDCES on social media

A Registered Dietitian and Certified Diabetes Educator at Good Measures, LLC, where she is a CDE manager for a virtual diabetes program. Campbell is the author of Staying Healthy with Diabetes: Nutrition & Meal Planning, a co-author of 16 Myths of a Diabetic Diet, and has written for  publications including Diabetes Self-Management, Diabetes Spectrum, Clinical Diabetes, the Diabetes Research & Wellness Foundation’s newsletter,, and

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