Wegovy (semaglutide) is a brand-name solution for a subcutaneous injection (shot) that’s prescribed for weight loss in some people. As with other drugs, Wegovy can cause side effects, such as nausea, vomiting, and diarrhea.

Wegovy is approved by the Food and Drug Administration (FDA) for long-term weight loss in certain adults and children ages 12 years and older. This medication should be used along with a low calorie diet and exercise to help manage your body weight.

Wegovy can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects won’t go away, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Wegovy in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Wegovy use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Wegovy’s prescribing information.

Mild side effects that have been reported with Wegovy include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Wegovy and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Wegovy may cause serious side effects. However, serious side effects weren’t common. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Wegovy’s prescribing information.

If you develop serious side effects while taking 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.

Serious side effects that have been reported and their symptoms include:

* Wegovy has a boxed warning for this side effect. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effect specifics” section below.
† An allergic reaction is possible after taking Wegovy. However, it’s not clear whether this side effect occurred in clinical trials. To learn more, see the “Side effect specifics” section below.

Side effects of Wegovy in children and adults are similar. However, children taking the drug in clinical studies were more likely to have gallbladder problems. This side effect was rare in this age group.

For more information about how side effects in children compare with those seen in adults, talk with your doctor or pharmacist. You can also view Wegovy’s prescribing information to view a full list of side effects reported by children and adults in clinical studies.

Learn more about some of the side effects that Wegovy may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Wegovy.

Risk of thyroid cancer

It’s possible for Wegovy to increase your risk of thyroid tumors, including thyroid cancer. In fact, Wegovy has a boxed warning for the risk of thyroid cancer. A boxed warning is the most serious warning recommended by the Food and Drug Administration (FDA). The purpose of a boxed warning is to alert patients and prescribers about the possible risks of taking a medication.

Although the risk of thyroid cancer hasn’t been seen in humans, it was reported in animal studies. However, it’s important to note that animal studies don’t always indicate what may happen in humans.

Symptoms of thyroid cancer can include:

What you can do

In some cases, doctors may recommend avoiding Wegovy. For example, if you have a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2, tell your doctor before taking Wegovy. In this case, you may be at a higher risk of developing thyroid cancer from taking Wegovy. So doctors typically won’t recommend Wegovy.

In addition, it’s important to be aware of any symptoms of thyroid cancer that you develop during your treatment. Your doctor can help determine what may be causing your symptoms. In some cases, they may recommend stopping treatment with Wegovy and trying a different option to manage your weight.

If you have additional concerns about Wegovy cancer side effects, talk with your doctor or pharmacist.

Nausea

You may experience nausea from taking Wegovy. Nausea was one of the most common side effects that people taking Wegovy reported in clinical trials. You may experience nausea more often when you first start taking Wegovy or when your doctor increases your dose.

What you can do

If you experience nausea from taking Wegovy, talk with your doctor or pharmacist. In rare cases, nausea may occur as a symptom of another side effect. For example, you may experience nausea from kidney problems, gallbladder problems, or pancreatitis.

If you have nausea during your treatment, your doctor can help determine what may be causing this side effect. They may also be able to recommend Wegovy nausea treatment.

Constipation

You may experience constipation during your treatment with Wegovy. In fact, constipation was one of the most common side effects in clinical trials of Wegovy. You may be at a higher risk of constipation when you first start taking Wegovy or when your doctor increases your dose.

What you can do

If you have constipation during your treatment with Wegovy, talk with your doctor or pharmacist. They may be able to recommend Wegovy constipation relief. For example, they may be able to recommend an over-the-counter (OTC) treatment for constipation, such as MiraLAX (polyethylene glycol).

Diarrhea

You may develop diarrhea from taking Wegovy. Diarrhea was one of the most common side effects reported in clinical trials. You may be at a higher risk of diarrhea occurring when you first start taking Wegovy or when your doctor increases your dose.

What you can do

If you notice diarrhea during your Wegovy treatment, talk with your doctor or pharmacist. They may be able to recommend ways to reduce this side effect. For example, your doctor or pharmacist may suggest taking an OTC treatment such as Imodium (loperamide) to treat your diarrhea.

Headache

It’s possible to develop headaches from taking Wegovy. Headaches were one of the most common side effects reported in clinical trials of Wegovy.

What you can do

If you develop headaches during your treatment with Wegovy, tell your doctor. In rare cases, headaches can occur due to a low blood sugar level. Your doctor can help determine what may be causing your headaches.

In addition, they may also be able to recommend ways to treat your headaches. For example, they may recommend taking an OTC treatment, such as Tylenol (acetaminophen).

Allergic reaction

As with most drugs, Wegovy can cause an allergic reaction in some people. However, how often this side effect occurred wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Wegovy. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

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Wegovy may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Are there reviews from people who experienced side effects with Wegovy injections?

If you’d like to learn more about what to expect from taking Wegovy, the best thing to do is to talk with your doctor. You may also be able to find testimonials online about side effects that people taking Wegovy reported.

However, it’s important to note that each person taking Wegovy may have their own experience with the drug since each person can respond to a medication differently. So online reviews of Wegovy written by other people may not be reliable sources for how your body will react to the drug.

If you have questions about side effects that you may experience with Wegovy, talk with your doctor or pharmacist.

Are there long-term side effects of Wegovy?

Although uncommon, it’s possible to experience long-term side effects from taking Wegovy. Examples of long-term side effects that may occur with this drug include:

If you are concerned about long-term side effects that may occur from taking Wegovy, talk with your doctor or pharmacist. They may also be able to recommend ways to limit these side effects occurring.

Before starting Wegovy, be sure to tell your doctor about any medical conditions that you have.

Boxed warning: Risk of thyroid cancer

This drug has a boxed warning for a risk of thyroid cancer. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section above.

Other precautions

Be sure to talk with your doctor about your health history before you take Wegovy. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Pancreas problems. Tell your doctor if you have any pancreas conditions, such as pancreatitis, before starting Wegovy. Although rare, it’s possible for Wegovy to cause pancreas problems to occur. And if you already have a pancreas condition, taking this medication can make your condition worse. If you have a pancreas condition, your doctor can help determine whether Wegovy may be safe for you.

Kidney problems. If you have any kidney problems, tell your doctor before taking Wegovy. This medication can cause kidney problems to occur and may make existing kidney problems worse. In this case, your doctor can help determine whether Wegovy may be safe for you.

Allergic reaction. If you’ve had an allergic reaction to Wegovy or any of its ingredients, your doctor will likely not prescribe Wegovy. Ask your doctor what other medications may be better options for you.

Diabetes. Tell your doctor if you have diabetes before starting Wegovy. It’s possible for this medication to cause a low blood sugar level, and this risk may be higher if you have diabetes. So your doctor may recommend monitoring your blood sugar level more often if you have diabetes and are taking Wegovy.

Diabetic eye problems. It’s possible for Wegovy to worsen diabetic retinopathy or a diabetic eye condition. So if you have this condition, taking Wegovy can make your symptoms worse. Due to this risk, your doctor may recommend monitoring your eyes more often while you’re taking Wegovy.

Depression or mood problems. Although rare, it’s possible for Wegovy to cause depression or increase your risk of suicidal thoughts. If you already have depression or a mood condition, taking Wegovy may make your condition worse. In this case, your doctor may recommend monitoring your mood more often while you’re taking Wegovy.

Wegovy side effects with alcohol

There aren’t any known interactions between Wegovy and alcohol. However, it’s possible that drinking alcohol while taking Wegovy may increase your risk of side effects from the drug. For example, both Wegovy and alcohol can cause:

If you consume alcohol, talk with your doctor to find out whether it’s safe to do so while taking Wegovy. They can also advise how much is safe.

Pregnancy and breastfeeding while taking Wegovy

Wegovy may not be safe to take during pregnancy. It’s also not known whether it’s safe to take Wegovy while breastfeeding.

There isn’t a benefit to losing weight during pregnancy, so your doctor likely won’t recommend taking this drug during pregnancy. They will likely recommend that you stop taking Wegovy at least 2 months before becoming pregnant.

In addition, animal studies show that there may be risks to a developing fetus if it is exposed to Wegovy. For example, in animal studies, there was an increased risk of congenital anomalies (also known as birth defects) and pregnancy loss. However, animal studies don’t always indicate what may happen in humans.

There is a pregnancy registry available for people who take Wegovy during pregnancy. A pregnancy registry is a collection of data that shows how a drug may affect a developing fetus. To join the pregnancy registry, call 877-390-2760 or talk with your doctor.

In addition, it’s not known whether Wegovy passes into breast milk or what effects the drug may have on a child who is breastfed. In animal studies, the drug was present in breast milk. However, animal studies don’t always indicate what may happen in humans.

If you’re pregnant or planning to become pregnant, talk with your doctor. You should also talk with them if you’re breastfeeding or considering it. Your doctor can help determine whether treatment with Wegovy is safe for you.

You may experience side effects from taking Wegovy. Although most side effects are mild, it’s possible for serious side effects to occur as well.

If you’d like to learn more about Wegovy, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today 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.