7 Insulin Detemir (Levemir) Side Effects You Should Know About

Insulin detemir (Levemir, Levemir FlexTouch) is one of several long-acting insulin options for managing Type 1 and Type 2 diabetes. As with all insulins, low blood sugar (glucose) is the most common side effect. But what other insulin detemir side effects should you know about?

Injection site reactions, headache, and upper respiratory tract infections are possible. And while weight gain is common with insulin, it may be less likely with insulin detemir compared to other longer-acting insulins. Serious side effects like severe low blood glucose and low potassium levels may need medical attention.

Fortunately, there are things you can do to lower the risk of side effects and get the most from treatment. Here we’ll discuss seven insulin detemir side effects and how to manage them.

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1. Low blood glucose

Low blood glucose (hypoglycemia) is the most common insulin detemir side effect. This is typically defined as having blood glucose levels below 70 mg/dL. When this happens, you may notice side effects like sweating, shaking, and a fast heartbeat.

There are a few factors that can raise the risk of hypoglycemia with insulin. Skipped meals, sickness, and alcohol are a few examples. Combining insulin with other diabetes medications can also make hypoglycemia more likely or worse.

Your healthcare provider will help you figure out a safe insulin detemir dose for you. It’s important to follow their instructions to prevent low blood glucose. They can also help you change your dosage as needed.

But if you experience hypoglycemia, you should treat it right away. Untreated hypoglycemia can turn into a serious problem. Follow your healthcare provider’s instructions for getting your blood glucose back up.

Consuming 15 g of fast-acting sugar (e.g., ½ cup fruit juice) is a good way to raise your blood glucose quickly. If your blood glucose is lower than 55 mg/dL, you may need help. Teach others to call 911 if you pass out, if you have trouble walking, or if you’re confused.

2. Injection site reactions

Like many injectable medications, insulin detemir can cause side effects where you inject it. These are often called injection site reactions. Symptoms can often include pain, itching, and swelling.

Most injection site reactions go away on their own within a day or two. If you have redness and swelling, try placing a cold compress on the area to help. Using proper injection technique can help limit these reactions.

Insulin detemir can be injected just under the skin of your thigh, upper arm, and abdomen. Rotating where you inject each time can also help.

But if your reaction isn’t going away, or if it’s getting worse, talk to your healthcare provider. They can recommend how to best manage it.

3. Lipodystrophy

Lipodystrophy is another possible insulin detemir side effect. If this happens, you might notice pits (indentations) or thickened skin where you’ve been injecting your insulin. Avoid injecting your dose into these areas, since you may not absorb it the same way.

There are a few factors that can raise the risk of lipodystrophy. Injecting in the same spot, reusing needles, and poor injection technique are a few examples. That’s why it’s important to rotate injection sites and use a new needle each time.

4. Headache

Headache is a common insulin detemir side effect. This can be caused by blood glucose changes in your body as you’re getting used to insulin. It’s possible that your blood glucose could be too low — or too high. If you feel a headache coming on, check your blood glucose levels to be sure.

If your insulin dose is too high or too low, your healthcare provider will help you make adjustments. Headaches will likely resolve as your blood glucose levels are more controlled.

But if you continue having headaches, talk with your healthcare provider. They can help figure out whether the headaches are from insulin detemir or another cause. They can also recommend treatments to offer short-term relief, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin).

5. Upper respiratory tract infections

Upper respiratory tract infections (URTIs) are another one of the most common side effects of insulin detemir. But you should also know that diabetes can raise your risk for infections overall.

Most URTIs (like the common cold) are caused by viruses and go away on their own. In this case, antibiotics won’t help treat the infection, and they aren’t recommended.

Treating URTIs often involves managing the symptoms, like sore throat, cough, and runny nose. Many over-the-counter (OTC) medications are available to help. Your healthcare provider can suggest options that are safe for you to take. But many of these OTC remedies contain glucose, so they could affect your blood glucose levels.

6. Weight gain

Most types of insulin can cause weight gain. This is also the case for insulin detemir. Insulin helps glucose from your blood enter your cells for energy. But excess glucose is turned into fat, which may lead to weight gain.

Insulin detemir may actually cause less weight gain than other insulins. It has been shown to cause less weight gain than insulin glargine (Lantus) and NPH insulin (Novolin N, Humulin N). Experts aren’t exactly sure why this is. But, it’s likely due to a complex interaction between the brain and your metabolic system.

During clinical trials, people with Type 2 diabetes taking insulin detemir gained about 1 lb to 2.5 lb of weight on average. Weight changes in people with Type 1 diabetes ranged from about 0.5 lb of weight loss to 1 lb of weight gain.

Maintaining a healthy diet and exercise regimen can help manage weight changes from treatment. Keeping your blood glucose levels under control is also important. If you’re concerned about weight gain from insulin detemir, your healthcare provider can give you tips to manage it.

7. Low potassium levels

All insulins can cause low potassium levels (hypokalemia). That’s because insulin causes potassium in your blood to move inside of your cells, lowering your blood potassium levels.

It’s uncommon for insulin detemir to cause hypokalemia on its own. But if you take other medications that lower potassium, you may be at risk. It’s also more likely to happen if you already have low potassium levels.

If your potassium levels aren’t very low, you may not have any symptoms. But if they get very low, your muscles, heart rhythm, and breathing may be affected.

Your healthcare provider may check your potassium levels while you’re taking insulin. Let them know right away if you notice any symptoms of hypokalemia, like muscle weakness.

When should I contact my healthcare provider about side effects from insulin detemir?

If you’re worried about side effects from insulin detemir, it’s a good idea to let your healthcare provider know. They can help you avoid or manage any side effects that you might experience moving forward.

If you’re having bothersome or persistent side effects during treatment, let your healthcare provider know right away. In some cases, your insulin dose may need to be adjusted.

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Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

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