Key takeaways

  • Wegovy (semaglutide) is considered a safe and effective treatment for the conditions it’s approved to treat.
  • Possible problems with long-term use include pancreatitis, gallbladder disease, and kidney damage.
  • The risk of serious problems from Wegovy treatment is low based on clinical trials. Before starting Wegovy treatment, discuss the possible risks with your doctor.

The Food and Drug Administration (FDA) has approved Wegovy for:

Based on clinical trials, the risk of serious problems from Wegovy is low. However, more long-term studies focusing on the drug’s side effects are necessary to understand the potential risks of long-term use.

This article centers on what’s currently known about the safety of Wegovy.

Wegovy is typically used as a long-term treatment, and its benefits generally outweigh the risks associated with it. In fact, the STEP-5 trial found that semaglutide (the active ingredient in Wegovy) is generally safe for treatment lasting at least 2 years, and side effects tend to decrease with time.

However, as with any drug, Wegovy can cause side effects in some people.

Reported side effects in clinical trials

Wegovy clinical trials for weight loss included 2,116 adults with overweight or obesity. Participants took 2.4 milligrams (mg) of Wegovy for up to 68 weeks (17 months), followed by a 7-week period without the drug.

In the trials, 6.8% of people who received Wegovy and 3.2% of people who received a placebo permanently stopped treatment due to negative side effects. The most common were gastrointestinal (GI) side effects, including nausea, vomiting, and diarrhea. These GI side effects were more likely after a dosage increase.

The most common side effects of Wegovy are GI issues, including:

These side effects are generally more common early in treatment and typically go away as your body gets used to the medication. They’re unlikely to continue long-term.

Other common side effects reported in Wegovy clinical trials include:

More serious and potentially long-term side effects of Wegovy include:

These side effects are typically very rare.

Voluntary reports

Side effects of a drug can also be reported voluntarily. For instance, after the FDA approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect during Wegovy treatment and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

There were no reports of the following serious side effects in clinical trials of Wegovy, but they have occurred since the drug was approved for use:

It’s not clear from the Wegovy prescribing information whether these effects are due to the drug or to another cause. Your doctor may be able to give you more information about this.

Semaglutide trial meta-analysis

A 2024 research review of nine studies of once-weekly semaglutide in people with overweight or obesity (but without type 2 diabetes) was carried out in 2024. This review found that the drug’s GI side effects are typically mild to moderate. The authors also found that the risk of serious side effects is not higher with semaglutide than with placebo.

However, a different research review from 2022 found a higher risk.

Both analyses report that semaglutide is a safe and effective treatment for weight loss, but some people may stop the drug because of side effects. More long-term studies on semaglutide are needed to know for sure whether Wegovy is safe to use long term.

For more information about the adverse effects of this medication and what to do about them, see this in-depth Wegovy side effects article.

Wegovy and Ozempic contain the same active ingredient: semaglutide. However, Wegovy and Ozempic have different doses and uses, so they may have slightly different side effects and safety profiles.

For example, Wegovy is FDA approved for weight loss in people ages 12 years and older. But the safety and effectiveness of Ozempic have not been established in people ages 18 years or younger.

Ozempic is not approved for weight loss, but some healthcare professionals prescribe it off-label for this use. (With off-label use, a drug is prescribed for a condition it hasn’t been approved to treat.)

The two medications also have different indications. For example, Wegovy is also approved to treat noncirrhotic MASH in adults, while Ozempic is not.

Some people should not use Wegovy due to certain risks associated with the drug. Talk with your doctor if either of these health factors applies to you.

Pregnancy

Wegovy is not suitable for anyone who is pregnant, as the drug may harm a fetus. If you’re planning a pregnancy, you should stop Wegovy treatment at least 2 months before becoming pregnant. For more information, see this in-depth article on Wegovy and pregnancy.

Thyroid cancer

Wegovy has a boxed warning about the risk of thyroid cancer. A boxed warning is the most serious warning from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

If you have risk factors for thyroid cancer, you should not use Wegovy. These factors include having a personal or family history of medullary thyroid carcinoma (MTC) and having a genetic condition called multiple endocrine neoplasia syndrome type 2 (MEN2) — a condition that can cause thyroid cancer.

Your doctor can advise you on Wegovy’s safety for treating your condition. If you experience severe side effects from this medication, your doctor may recommend that you stop treatment and suggest other treatment options for your condition.

Wegovy is typically considered very safe and effective for long-term use. Its most common side effects are gastrointestinal effects, and these are most associated with early treatment while your body adjusts to the drug. These effects go away with time.

However, as with all medications, Wegovy has a risk of rare, serious effects. If you think you’re experiencing a side effect, speak with your doctor. You can also report the side effect to the FDA.

Disclaimer: While Medical News Today strives for factual, comprehensive, and current drug information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.