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Wegovy Side Effects

Generic name: semaglutide

Written by Kristianne Hannemann, PharmD on March 18, 2025.

Important warnings This medicine can cause some serious health issues

Warning: Risk of Thyroid C-Cell Tumors.

In rodents, semaglutide causes thyroid C-cell tumors.

It is unknown whether semaglutide causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as the human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined.

Semaglutide is contraindicated in patients with a personal or family history of MTC or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

Wegovy (semaglutide) is a medication commonly prescribed for weight loss and maintaining weight loss long-term in people 12 years and older with obesity or certain adults who are overweight. It can reduce the risk of major adverse cardiovascular events, such as heart attack and stroke, in adults with heart disease and obesity or who are overweight. While effective, it can cause a range of side effects. This guide will help you understand the potential side effects of Wegovy, both common and serious, and provide tips for managing them. Always consult your healthcare provider if you experience any symptoms that are severe or persistent.

Common side effects

Common side effects of Wegovy are generally mild to moderate and include:

These side effects are often manageable with simple lifestyle adjustments and over-the-counter remedies.

View common side effects (in more detail).

Serious side effects

Although less common, Wegovy can also cause more serious side effects that may require immediate medical attention. These include:

Additionally, animal studies suggest Wegovy has the potential to cause thyroid cancer, which may lead to lumps in the throat and difficulty swallowing. It's important to be aware of these potential risks and consult your healthcare provider if you experience any severe symptoms.

View serious side effects (in more detail).

Common side effects in more detail

Nausea and vomiting

Nausea from Wegovy is a common side effect, occurring in 44% of adults and 42% of children 12 years and older. For most people, the nauseous feeling is mild to moderate. However, 24% of adults and 26% of adolescents reported vomiting during clinical studies of Wegovy. Nausea and vomiting is most common early on during treatment when you are raising your dose up to the maintenance dose. Many people who experience nausea from taking Wegovy feel better within a week. If you experience nausea that is severe or persistent, contact your healthcare provider.

Tips for managing nausea and vomiting

Wegovy users reporting nausea and vomiting

Diarrhea

Another common side effect of Wegovy is diarrhea. During clinical trials, 30% of adults and 22% of adolescents reported having diarrhea. For most people, diarrhea is mild to moderate. You may experience frequent, loose, or watery stools after starting Wegovy. This is most common during the first weeks of taking it, and should get better over time.

Tips for managing diarrhea

Wegovy users reporting diarrhea

Constipation

Constipation from Wegovy is another stomach-related side effect you may experience. It occurs in 24% of adults and 6% of adolescents. You may have infrequent or difficult bowel movements. Most people experience constipation during the first few months of treatment, while the dose is being increased. It usually gets better with time, but if you continue to have constipation you should tell your healthcare provider.

Tips for managing constipation

Wegovy users reporting constipation

Stomach pain

Another common side effect from Wegovy is stomach pain, with 20% of adults and 15% of adolescents reporting it during clinical trials. You may experience discomfort or cramping in the stomach area. It is most common to experience stomach pain during the first few months of treatment with Wegovy. This side effect may get better as your body gets used to the medication. Contact your healthcare provider if stomach symptoms are getting worse or not getting better after some time on Wegovy.

Stomach pain can be a sign of pancreatitis (inflammation of the pancreas), which requires immediate medical attention. Seek medical attention if you have severe stomach pain with or without vomiting.

Tips for managing stomach pain

Wegovy users reporting stomach pain

Headache

Wegovy can commonly cause headaches as a side effect. In clinical trials, 14% of adults and 17% of adolescents experienced headache during treatment with Wegovy. You may experience a sharp pain or dull ache. Some people also feel a throbbing sensation in their head. It is not clear why this happens, but there are some ways you can manage your headache pain at home. Tell your healthcare provider if your headache seems severe, or is not going away.

Tips for managing headache

Wegovy users reporting headaches

Fatigue

Wegovy can make some people feel more tired than usual. This is more common in adults. In studies, 11% of adults reported fatigue as a side effect. You may have less energy, which might be due to your appetite being lower compared to normal. When you eat less food, you tend to have less energy and feel tired during the day. Consult a healthcare provider if fatigue persists.

Tips for managing fatigue

Wegovy users reporting fatigue

Indigestion

Indigestion is another common side effect from Wegovy, with 9% of adults experiencing it. You might feel a sensation of having eaten too much food, feel bloated, or have acid reflux. This may happen because Wegovy slows down stomach emptying. These symptoms are common in the beginning of treatment with Wegovy, and may improve as you continue to take the medication. Tell your healthcare provider if your symptoms are very bothersome or are not getting better after a few weeks.

Tips for managing indigestion

Wegovy users reporting heartburn

Dizziness

Wegovy can cause dizziness. During clinical trials, 8% of adults and 8% of adolescents reported dizziness as a side effect. You might feel lightheaded or unsteady. Tell your healthcare provider if you feel very dizzy or if it keeps happening.

Dizziness can be a symptom of low blood sugar, which is more common if you are taking Wegovy with certain other diabetes medications (e.g., insulin, sulfonylurea). If you feel dizzy, check your blood sugar to make sure it is within a normal range.

Tips for managing dizziness

Wegovy users reporting dizziness

Burping

Burping is another common and mild side effect of Wegovy, with it occurring in 7% of adults and 4% of adolescents. Burping is how the body releases excess air from the stomach. While not harmful, it can be bothersome.

Tips for managing dizziness

Wegovy users reporting burping

Serious side effects in more detail

Hypoglycemia

Hypoglycemia (low blood sugar) from Wegovy is a side effect that is more likely in people with type 2 diabetes when used with insulin or sulfonylureas. Wegovy causes hypoglycemia in 6% of patients with type 2 diabetes. Most cases of hypoglycemia are mild or moderate, but severe cases do happen. There were no cases of hypoglycemia in people without type 2 diabetes during clinical trials.

If you experience symptoms of hypoglycemia (e.g., shakiness, sweating, blurry vision, dizziness), check your blood sugar level. If your blood sugar is low (70 mg/dL or less), take 15 grams of fast-acting carbohydrates. Wait 15 minutes and check your blood sugar level again. Get emergency medical help if you are not responding to fast-acting sugar sources or if your blood sugar level is below 55 mg/dL. Consult your healthcare provider for dose adjustments if needed.

Wegovy users reporting hypoglycemia

Allergic reactions

Severe allergic reactions to Wegovy are rare. In clinical trials, 3% of adolescents experienced a rash and 3% of patients experienced hives. More serious reactions were rarely reported. If you experience allergy symptoms such as hives, swelling in your face or throat, or trouble breathing, stop using Wegovy and seek immediate medical attention.

Tachycardia

Some people who take Wegovy may experience an increase in their heart rate of about 1 to 4 beats per minute. Tachycardia from Wegovy is rare. Monitor your heart rate, avoid stimulants, and consult your healthcare provider if you experience persistent or severe symptoms.

Wegovy users reporting heart rate

Vision changes

When blood sugar levels improve too quickly, some people with type 2 diabetes experience a temporary worsening of diabetic retinopathy. If this happens, you may notice blurry vision or other changes to your vision. Complications of diabetic retinopathy occur in 3% of patients taking Wegovy. Contact your healthcare provider if you notice any unusual changes in your vision.

Wegovy users reporting blurred vision

Pancreatitis

Pancreatitis from Wegovy is a rare side effect, occurring in less than 1% of patients. Signs of pancreatitis include severe stomach pain and vomiting. Seek immediate medical attention if you experience these symptoms. If you do develop pancreatitis while taking Wegovy, it is not recommended to start the medication again.

Gallstones

Rarely, patients taking Wegovy experience gallstones. Gallstones occur in less than 2% of patients taking Wegovy. Contact your healthcare provider for further evaluation if you experience severe abdominal pain, fever, clay-colored stools, or yellowing of your skin or whites of your eyes.

Kidney damage

Rarely, some patients taking GLP-1 receptor agonists like Wegovy have reported kidney injury and worsening kidney function. Because Wegovy can cause nausea, vomiting, and diarrhea as side effects, you are more likely to become dehydrated. Dehydration can contribute to kidney injury. Make sure to stay hydrated and consult your healthcare provider if you experience symptoms such as swelling or changes in urination.

Wegovy users reporting kidney issues

References

Frequently asked questions

Further information

Wegovy side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer