7 Tresiba Side Effects and Tips for Preventing Them

Insulin is a life-saving medication for many people living with diabetes. Tresiba (insulin degludec) is a long-acting insulin approved for people age 1 and older. It’s injected once daily and provides blood glucose control for 42 hours. Tresiba is available in 100 units per mL (U-100) and 200 units per mL (U-200) formulations.

Like all medications, Tresiba has potential side effects. Most of these are generally mild and can be managed at home. But others, like hypoglycemia (low blood glucose), can become severe if not addressed right away. Knowing what to expect can help you react appropriately if side effects occur.

Tresiba side effects at a glance

Tresiba can cause both mild and potentially serious side effects. Examples of mild Tresiba side effects include:

• Common cold

• Headache

• Diarrhea

• Weight gain

• Lipodystrophy

• Injection site reactions

• Swelling

• Rash

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Examples of potentially serious Tresiba side effects include:

• Hypoglycemia

• Allergic reactions

• Low potassium levels

Many Tresiba side effects resolve over time or can be managed by following a few tips, such as rotating injection sites and using a proper injection technique. We cover what you can do to manage seven of these Tresiba side effects below.

1. Hypoglycemia

Hypoglycemia is a potential side effect of all insulins, including Tresiba. Hypoglycemia occurs when your blood glucose is below 70 mg/dL. This can happen due to a variety of factors, such as taking too much insulin, eating too few carbohydrates, and unexpected changes in your schedule. 

Compared to other long-acting insulins, like Lantus (insulin glargine), Tresiba may carry a lower risk of hypoglycemia. This can make it a good option for people who have a higher hypoglycemia risk, including older adults and people with kidney problems. And Tresiba U-200 can be a good option if you need higher insulin doses.

Shakiness, sweating, and hunger are often telltale signs of hypoglycemia. Though, some people don’t experience these symptoms and may have trouble telling their blood glucose is too low as a result. In this case, wearing a continuous glucose monitor or checking blood glucose regularly can help identify hypoglycemic episodes.  

If your blood glucose drops below 70 mg/dL, make sure you know how to handle a hypoglycemic episode. Blood glucose below 55 mg/dL is typically considered severe and may require medical assistance.

Let your healthcare provider know if you’re experiencing frequent hypoglycemic episodes. They may recommend a lower Tresiba dose. 

2. Common cold

You may experience common cold symptoms with Tresiba. Other upper respiratory tract infections (URTIs) have also been reported with the medication. These types of infections are usually caused by viruses, so it’s not necessary to take antibiotics. Symptoms like a runny nose, sore throat, and nasal congestion can be bothersome, but they usually only last about a week.

Over-the-counter (OTC) remedies may help lessen the symptoms of a URTI until you start feeling better. Talk to your healthcare provider or pharmacist about which OTC options are safe for you to take. Some cold and flu medications aren’t ideal or safe for people who have diabetes.

If your symptoms worsen or don’t seem to be improving after 10 days, let your healthcare provider know. It’s possible that you could have a bacterial infection that requires antibiotics.

Keep in mind: In general, diabetes can increase your risk of getting an infection. So it’s important to protect yourself from preventable illnesses by staying up to date with vaccinations, such as your annual flu shot.

3. Headache

Headache is a common Tresiba side effect, especially when you first start taking it and after dose changes. But the headaches usually go away as your body gets used to the medication. 

If your headaches are significant enough to get in the way of your usual activities, talk to your healthcare provider. They may suggest trying an OTC pain reliever, like acetaminophen (Tylenol). But be careful if you’re also taking an OTC medication for cold symptoms. Many of these medications already contain a pain reliever.

Keep in mind that headaches can also be a symptom of either low or high blood glucose. If your headaches are persistent or accompanied by other symptoms, such as weakness or blurry vision, check your blood glucose. And then, follow the instructions given to you by your healthcare team based on the reading.

4. Diarrhea

Diarrhea is a possible Tresiba side effect. You may experience loose and watery stools, or abdominal pain and bloating, while taking the medication. However, it’s important to note that diabetes can also cause diarrhea, especially if you’ve been living with the condition for a while.

Diarrhea can sometimes lead to fluid loss, so it’s important to stay hydrated. You may be able to improve your diarrhea symptoms by making changes to your diet. For example, you can try avoiding fried or fatty foods. Your provider may suggest sticking with a simple, bland diet for a few days. But if your diarrhea doesn’t go away after a few days, let your healthcare team know. 

Your healthcare provider can help you pinpoint what’s causing your diarrhea. And, if needed, they may recommend an OTC antidiarrheal medication. 

5. Weight gain

Weight gain is a common side effect of Tresiba and all other insulins. This is because insulin helps the glucose in your blood move into your cells. Excess glucose may get stored as fat and result in weight gain. On average, people taking insulin gain 4 lbs within the first year. But some people gain a bit more.

Having a diabetes-friendly diet and doing regular physical activity are important parts of staying healthy, as well as managing your blood glucose and weight. But if weight gain from Tresiba is a concern for you, your healthcare provider may suggest making changes to your routine to help prevent or manage weight gain.

6. Lipodystrophy

Another possible Tresiba side effect is lipodystrophy. This is a problem of fat distribution. It often affects areas of the skin where insulin is injected. This can look like indentations in the skin or thickened skin where you’ve been injecting insulin.

To prevent lipodystrophy, always rotate your injection site and only use a needle one time. If you develop lipodystrophy, don’t inject into an area of uneven fat distribution. This can affect how you absorb your insulin dose.

7. Injection site reactions

Injection site reactions are possible with Tresiba. Common symptoms of these reactions include pain, itching, and swelling in the area where you inject Tresiba. You may also experience redness or warmth at the injection site.  

Common Tresiba injection areas are the stomach, thighs, and upper arms. To lower the risk of injection site reactions, rotate spots in the injection area, using a different one each time. If you store your unopened Tresiba in the refrigerator, allow it to come up to room temperature before injecting a dose to lessen stinging.

Injection site reactions usually go away within a few days. An ice pack or a warm compress may help relieve the soreness. Your pharmacist can also recommend an OTC pain reliever or anti-itch medication that’s safe for you to take.

Good to know: If you develop other symptoms, including trouble breathing or hives, you may be having an allergic reaction. Get immediate medical attention if this occurs.

When should you contact your healthcare provider about Tresiba side effects?

Many Tresiba side effects, such as injection site reactions and headaches, are mild and usually resolve on their own. But if any of your side effects seem worrisome or severe, let your healthcare provider know. They may consider adjusting your dose or recommending other treatment options.

You should also contact your healthcare provider if you’re experiencing frequent hypoglycemic episodes. This can be a sign that your Tresiba dose is too high. Your healthcare provider can help you determine how best to avoid episodes of hypoglycemia. 

Don’t attempt to stop taking Tresiba or change your dose without consulting your healthcare provider first.

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Written by:

Julie Adkison, PharmD, BCACP, CDCES

Julie Adkison, PharmD, BCACP, CDCES, is a clinical pharmacist specializing in ambulatory care practice and diabetes care and education. She has worked in a faculty position in family medicine for many years.

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:

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.

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