Key Takeaways

  • Side effects of Wegovy can range from mild to severe. Some of the most common side effects include headache, nausea, vomiting, and abdominal pain.
  • It’s possible to have long-term side effects while taking Wegovy. It’s also possible for some side effects, such as nausea and vomiting, to go away as your body gets used to the drug.
  • Possible serious side effects include low blood sugar, gallbladder problems, and pancreatitis.

Wegovy is approved for the following uses:

Doctors usually prescribe Wegovy long term as part of a treatment plan that includes an increase in physical exercise and a low calorie diet.

Keep reading to learn about the common, mild, and serious side effects that Wegovy can cause. For a general overview of the drug, including details about its uses, see this Wegovy overview.

Wegovy has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Understanding and managing side effects” section.

Some people may experience mild to serious side effects during their Wegovy treatment. Others may not have any side effects at all. Examples of Wegovy’s commonly reported side effects include:

For more information about some of these side effects, see the “Understanding and managing side effects” section.

Examples of mild side effects that have been reported with Wegovy include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop using Wegovy unless your doctor recommends it.

For more information about some of these side effects, see the “Understanding and managing side effects” section.

Wegovy may cause mild side effects other than the ones listed above. See the drug’s prescribing information for details.

Wegovy may cause serious side effects, but these are rare.

Serious side effects that have been reported with this drug include:

If you develop serious side effects while using Wegovy, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Wegovy and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Wegovy can cause an allergic reaction. In general, symptoms of allergic reaction can be mild or serious.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep using Wegovy.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Wegovy, they may have you switch to a different treatment.

Yes, it’s possible for Wegovy to cause long-term side effects. This can refer to side effects that last a long time, or side effects that develop after long-term use of Wegovy. Some long-term side effects of Wegovy that may start during treatment include:

Talk with your doctor if you have concerns about possible long-term side effects from using Wegovy.

How long does it take for side effects of Wegovy to go away?

It varies. Some people may have side effects from Wegovy, and others may not. Some side effects may clear up in a few weeks as your body gets used to the drug, or last as long as you use Wegovy. In the drug’s studies, it’s not known exactly when each side effect was reported.

If you have questions about how long Wegovy side effects may take to go away, talk with your doctor.

In general, Wegovy’s side effects are expected to be similar in children and adults. In studies, the following side effects were also reported in children ages 12 years and older who used Wegovy:

Gallbladder problems were more common in children than in adults taking Wegovy in studies.

The price you’ll pay for Wegovy can vary. Your cost may depend on your treatment plan, the pharmacy you use, and any insurance coverage you have.

To save money on your Wegovy treatment, explore the following coupon options. (Note: Optum Perks coupons cannot be used with any insurance copays or benefits.)

Get answers to some frequently asked questions about Wegovy’s side effects.

Does Wegovy make you tired?

This is possible. Fatigue (feeling tired or like you lack energy) was reported as a side effect in Wegovy’s studies.

If you feel like Wegovy treatment is making you tired, you can try making some lifestyle changes to help manage this. For example, make sure you’re eating healthy foods, drinking enough water, and exercising. Also, discuss your fatigue with your doctor so that they can help you manage it.

When do Wegovy side effects start?

It can vary. Side effects may occur at any time during Wegovy treatment. Digestive side effects, such as nausea, are more common during the first 4 months of treatment. These side effects usually get better on their own over time.

It’s also possible that you won’t experience any side effects at all during long-term Wegovy treatment.

To help lower the risk of side effects, be sure to use Wegovy according to your doctor’s instructions.

Learn more about some of the side effects Wegovy may cause.

Wegovy rash

It’s possible for Wegovy to cause a skin rash. In studies, some children taking Wegovy developed a rash or a type of rash called hives. This can cause areas of skin that are red, itchy, swollen, or irritated.

A rash can be a sign of an allergic reaction, which can become life-threatening. Other allergic reaction symptoms can include swelling in your face or throat, trouble breathing, chest tightness, nausea, and vomiting.

What might help

If you develop a rash or hives, contact your doctor. They can recommend whether to start treatment for a possible allergic reaction. Be sure to watch for any other symptoms that may develop.

Your doctor might recommend some ways to help with a rash, depending on the cause, such as taking an oatmeal bath or using medications.

Risk of thyroid cancer

Wegovy has a boxed warning about the risk of thyroid C-cell tumors. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

In studies, Wegovy caused thyroid C-cell tumors in animals. (C cells are a kind of cell in the thyroid gland.) This side effect depended on Wegovy’s dosage and length of treatment. It’s not known if the same effect would happen in humans.

Because of this potential risk, doctors usually won’t prescribe Wegovy to people with a higher risk of medullary thyroid carcinoma (MTC). This includes people who:

What might help

Tell your doctor right away if you notice the following symptoms while using Wegovy:

Nausea and vomiting

In studies of Wegovy, nausea and vomiting were commonly reported side effects. They were also the most common reason that people stopped treatment with Wegovy.

Nausea and vomiting are more common during the first few months of Wegovy treatment, especially with dose increases during the first 4 months. These side effects usually go away over time as your body gets used to the medication and dosage. So, nausea with Wegovy could last for a few weeks to several months, or possibly longer.

Symptoms include:

  • lack of appetite
  • sweating
  • abdominal pain
  • retching

What might help

Talk with your doctor about nausea that doesn’t reduce or becomes bothersome. You can also try some things that might help you avoid feeling sick with Wegovy, such as:

  • drinking small sips of ice-cold drinks
  • avoiding greasy, fatty foods
  • eating bland foods, such as crackers, rice, applesauce, or bananas
  • avoiding physical activity after eating

To avoid dehydration from vomiting, drink plenty of water, juices, sports drinks, or broth, and avoid caffeine and alcohol (if you drink).

Wegovy diarrhea

Diarrhea was a commonly reported side effect in Wegovy’s studies. Symptoms can include:

  • cramping or pain in the abdomen
  • frequent, loose, watery stools
  • dehydration from loss of fluids

What might help

If you have diarrhea that doesn’t go away, talk with your doctor. It’s important to stay hydrated if you have diarrhea. Drink plenty of water, juices, sports drinks, or broth, and avoid caffeine and alcohol.

Constipation

In Wegovy’s studies, constipation was a commonly reported side effect. Symptoms can include:

  • experiencing a change or decrease in how many bowel movements you have per day
  • having less than three bowel movements per week
  • passing stool that’s hard or lumpy
  • straining to have a bowel movement
  • feeling unable to empty your bowels

What might help

To ease constipation, you can try:

  • increasing the amount of water you drink
  • increasing physical activity, such as exercising
  • eating more fiber

If you’d like to try an over-the-counter medication for constipation, talk with your doctor or pharmacist first. They’ll ask about other medications you take to make sure there are no drug interactions.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

Consider the following important information before starting Wegovy.

Wegovy has a boxed warning for the risk of thyroid C-cell tumors. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Understanding and managing side effects” section.

Other precautions

Before taking Wegovy, discuss your health history with your doctor. Wegovy may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.