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Safety

Is Wegovy safe? What the FDA label and the trials show

Wegovy has one of the larger safety records of any weight-loss drug, including a heart-outcomes trial of 17,604 people. "Safe" still comes with conditions. Here's what the US label warns about, how often problems showed up, and who the label rules out.

Marisol Keane

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The short answer

For most adults it's prescribed to, Wegovy has a well-studied safety record and mostly digestive side effects. It isn't safe for everyone. Its label carries a boxed warning about rodent thyroid tumors, rules it out with a history of medullary thyroid cancer or MEN 2, and lists rare serious risks like pancreatitis, gallbladder disease and kidney injury from dehydration.

Key takeaways

  • Wegovy is FDA-approved. In the SELECT trial, semaglutide 2.4 mg lowered major cardiovascular events from 8.0% to 6.5% in adults with heart disease and overweight or obesity.
  • Its boxed warning covers thyroid C-cell tumors seen in rodents; whether that happens in people "has not been determined."
  • The label rules it out with a personal or family history of medullary thyroid cancer or MEN 2, or a prior serious allergy to semaglutide.
  • Most side effects are digestive: nausea 44%, diarrhea 30%, vomiting 24% and constipation 24%, vs 16%, 16%, 6% and 11% on placebo. About 7 in 100 stopped because of side effects.
  • In February 2026 the suicidal behavior and ideation section was removed from Wegovy's warnings.

Wegovy is semaglutide, the same molecule as Ozempic, under a label written for weight and heart risk. FDA approved it because the agency judged that its benefits outweigh its risks for the people on that label [1]. Whether it's safe for you depends on your history, your other medicines and how your body handles the first months. The molecule itself is covered in semaglutide, and the brand in Wegovy.

Approved, with conditions

FDA approval means the agency reviewed the trial data and found the benefits outweigh the risks for the people on the label. It doesn't mean nothing can go wrong. The label lists a boxed warning, two contraindications and eleven numbered warnings, and each one tells you something about who should be careful [1].

The short version: most people who take Wegovy get stomach side effects, usually mild and usually while the dose is going up. A small number get something serious, and a few groups shouldn't take it at all.

What the trials showed on safety and benefit

In the 68-week weight trials pooled on the label, 6.8% of people on Wegovy 2.4 mg stopped because of side effects, against 3.2% on placebo [1]. That's about 7 in 100 versus 3 in 100. Nausea, vomiting and diarrhea were the most common reasons.

The benefits are on the other side of the ledger. In STEP 1, adults without diabetes lost an average 14.9% of their body weight over 68 weeks on semaglutide 2.4 mg, against 2.4% on placebo [2]. In SELECT, 17,604 adults aged 45 and older with heart disease and overweight or obesity, but no diabetes, were followed for a mean of 39.8 months. Heart attack, stroke or cardiovascular death occurred in 6.5% on semaglutide and 8.0% on placebo, a hazard ratio of 0.80 [3]. Both trials were funded by Novo Nordisk, which makes Wegovy.

Wegovy benefits and risks, by the numbers
OutcomeWegovy 2.4 mgPlaceboSource
Average weight change at 68 weeks (STEP 1)−14.9%−2.4%STEP 1 [2]
Heart attack, stroke or cardiovascular death (SELECT)6.5%8.0%SELECT, hazard ratio 0.80 [3]
Stopped because of side effects6.8%3.2%Label, weight trials [1]
Any digestive side effect73%47%Label [1]
Severe digestive side effects4.1%0.9%Label [1]
Gallstones (cholelithiasis)1.6%0.7%Label [1]
Gallbladder inflammation (cholecystitis)0.6%0.2%Label [1]
Acute kidney injury0.4 per 100 patient years0.2 per 100 patient yearsLabel [1]
Low blood pressure1.3%0.4%Label [1]

Label rates come from adult weight-reduction trials of the 2.4 mg injection. STEP 1 and SELECT were funded by Novo Nordisk.

SELECT also tells you something about tolerability over years: 16.6% on semaglutide stopped the trial drug because of side effects across the whole trial, against 8.2% on placebo [3]. Longer trials catch more stopping than the 68-week label pool.

The boxed warning is about thyroid tumors in rodents

Wegovy's boxed warning comes from animal studies. In the label's words, “In rodents, semaglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures.” It adds that “human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined” [1].

So the honest answer is that no one knows whether this happens in people. The label notes reports of medullary thyroid cancer with liraglutide, an older drug in the same class, and says the data “are insufficient to establish or exclude a causal relationship.” It asks prescribers to tell patients about the symptoms of thyroid tumors: “a mass in the neck, dysphagia, dyspnea, persistent hoarseness” [1]. In plain words, a lump in your neck, trouble swallowing, shortness of breath or hoarseness that won't go away. The thyroid question gets its own page in Wegovy and thyroid cancer.

The label's other warnings are mostly uncommon

Beyond the thyroid warning, Wegovy's label lists ten more, numbered 5.2 to 5.11 [1]. Most are rare. Here's each one in a line.

  • Pancreatitis. Watch for “persistent or severe abdominal pain (sometimes radiating to the back)”. Adjudicated cases ran at 0.2 per 100 patient years on Wegovy.
  • Gallbladder disease. Gallstones in 1.6% vs 0.7% on placebo. Details in Wegovy and your gallbladder.
  • Low blood sugar. The risk rises mainly when Wegovy is combined with insulin or a sulfonylurea.
  • Kidney injury from dehydration. Vomiting and diarrhea can drain fluids; see does Wegovy make you pee more.
  • Severe digestive reactions. 4.1% vs 0.9%, and Wegovy “is not recommended in patients with severe gastroparesis.” More in Wegovy nausea and constipation.
  • Allergic reactions. Anaphylaxis and angioedema have been reported.
  • Eye complications in type 2 diabetes. People with diabetic retinopathy should be monitored.
  • Faster heart rate. Resting heart rate rose by 1 to 4 beats per minute on average.
  • Food in the lungs under anesthesia. Rare reports; tell every clinician you take Wegovy before surgery or sedation.
  • Never share a FlexTouch pen, even with a new needle, because of the risk of passing on blood-borne infections.

In February 2026, the suicidal-ideation warning came off the label

Wegovy's label used to carry a warning section on suicidal behavior and ideation. Its Recent Major Changes list now reads: “Suicidal Behavior and Ideation (5.10)……(Removed) 02/2026” [1]. The never-share-a-pen warning, now numbered 5.11, was added in June 2026.

The label itself doesn't explain the removal, so this page doesn't either. If you've had depression or suicidal thoughts, that's still worth raising with your prescriber, as it would be with any new long-term medicine.

Who should not take Wegovy

The label's two contraindications are firm. Wegovy is ruled out for anyone with “a personal or family history of MTC or in patients with MEN 2”, and for anyone with “a prior serious hypersensitivity reaction to semaglutide or to any of the excipients” [1]. MTC is medullary thyroid carcinoma; MEN 2 is an inherited condition that causes tumors in hormone glands.

Pregnancy deserves its own line. The label says Wegovy “may cause fetal harm” and, for weight or heart-risk use, to stop it when pregnancy is recognized [1]. Because semaglutide stays in the body a long time, the two-month gap before trying to conceive matters.

Common side effects are mostly digestive

Most of what people feel on Wegovy happens in the gut, and it's most frequent while the dose is being raised. In the label's weight trials, 44% had nausea, 30% diarrhea, 24% vomiting and 24% constipation, against 16%, 16%, 6% and 11% on placebo [1]. Headache (14% vs 10%), fatigue (11% vs 5%) and dizziness (8% vs 4%) were next.

How long the stomach symptoms last, and when they're a warning sign, is covered in Wegovy nausea, constipation and diarrhea. The full list, including the 7.2 mg dose, is in Wegovy side effects.

Does Wegovy cause…? A symptom lookup

Many symptoms people ask about don't appear in Wegovy's prescribing information. That doesn't prove there's no link. It means the trials didn't flag them often enough to list, and nothing in the label ties them to the drug.

Is it in Wegovy's label?
SymptomIn the label?What the label says
Hair lossYes3% vs 1% on placebo with the 2.4 mg injection; linked to weight reduction
Injection-site reactionsYes1.4% vs 1% on placebo (itching, redness, irritation)
TirednessYesFatigue 11% vs 5%
HeadacheYes14% vs 10%
DizzinessYes8% vs 4%; low blood pressure 1.3% vs 0.4%
Urinary tract infectionOnly in teens4% vs 2% in the trial of children 12 and older; not listed for adults
Joint pain, back pain, leg cramps, body achesNoNot listed
Blood clots, chest painNoNot listed
Low sex drive, acne, hot flashes, migraines, brain fog, vertigoNoNot listed
Blood in your stoolNoNot listed; see a clinician promptly, whatever the cause
Can it cause diabetes?NoIt lowers blood sugar; low blood sugar is the risk, mainly with insulin or a sulfonylurea

Rates are adult weight-reduction trials of the 2.4 mg injection unless noted [1]. "Not listed" means not found in the prescribing information or Medication Guide. Report anything new to your prescriber, and to FDA's MedWatch program [6].

Does the shot hurt? Injection-site reactions such as itching, redness or irritation were reported by 1.4% of people on Wegovy and 1% on placebo [1]. That's close to placebo, which suggests the needle matters more than the drug.

Most of the weight tends to come back after stopping

Stopping Wegovy isn't dangerous in itself, but the weight usually returns. In the STEP 1 extension, people who came off semaglutide had lost 17.3% by week 68 and regained 11.6 percentage points of it by week 120. The authors summed it up as regaining “two-thirds of their prior weight loss” [4]. Improvements in blood pressure and other heart-risk markers also drifted back toward where they started.

Feeling hungry on Wegovy isn't a safety signal either. Responses vary, and if hunger doesn't settle, that's worth raising with your prescriber. What Wegovy costs month to month is in what Wegovy costs.

This safety record belongs to Wegovy itself

Everything above comes from trials of Novo Nordisk's product. Compounded semaglutide is a pharmacy-made version that FDA doesn't review for safety, effectiveness or quality before it's sold. FDA has described its own concerns, including adverse-event reports, some needing hospital care, that may be tied to dosing errors with compounded semaglutide injections [5]. Those risks are covered in is compounded semaglutide safe and compounded semaglutide. The tablet version of Wegovy is covered in oral semaglutide.

Compare before you sign up: 21 brand Wegovy and Zepbound self-pay programs, scored on price, care and pharmacy checks.

Providers that offer Wegovy

  • Maximus

    You want a brand GLP-1 pill such as Foundayo or Wegovy tablets at a printed cash price, from a provider that names its pharmacies.

    Maximus review →
  • AgelessRx

    You want a longevity-focused program for rapamycin or metformin with labs built in, or brand Wegovy pill access with a clear monthly total.

    AgelessRx review →
  • Ro

    You want an FDA-approved GLP-1, such as the Wegovy pill, Foundayo or Zepbound, at a published cash price for each dose, or help getting a pen covered by insurance.

    Ro review →
  • Heally

    You want to talk through off-label rapamycin or metformin with a physician in a live visit, with the medication and visit bundled at a printed monthly price.

    Heally review →
  • MEDGmPartner

    You want labs, clinician visits, side-effect medicine and shipping in one monthly price that holds at every dose, from a program that names its pharmacies.

    MEDGm review →

See all 21 providers on the brand Wegovy and Zepbound lineup →

Frequently asked

Is Wegovy safe long term?
The longest large trial, SELECT, followed people for a mean of 39.8 months and found fewer heart attacks, strokes and cardiovascular deaths on semaglutide. Beyond about three to four years, there's less trial data.
Does the Wegovy shot hurt?
Injection-site reactions, such as itching, redness or irritation, were reported by 1.4% of people on Wegovy and 1% on placebo. Most people don't report a problem at the injection site.
Can Wegovy cause blood clots?
Blood clots aren't listed in Wegovy's prescribing information. If you have leg swelling, chest pain or sudden shortness of breath, get medical help right away, whatever you think the cause is.
Is Wegovy safe if I have diabetes?
Wegovy was studied in adults with type 2 diabetes. The label flags two things: low blood sugar is more likely with insulin or a sulfonylurea, and people with diabetic retinopathy should be monitored.
Is Wegovy safer than compounded semaglutide?
Wegovy's safety data come from FDA-reviewed trials of the finished product. Compounded semaglutide isn't reviewed by FDA before it's sold, so no comparable data exist for it.

Sources

  1. [1] Wegovy (semaglutide) injection and tablets, prescribing information and Medication Guide (version 19, June 2026) (2026). DailyMed label
  2. [2] Wilding JPH. Once-Weekly Semaglutide in Adults with Overweight or Obesity (2021). PMID 33567185
  3. [3] Lincoff AM. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (2023). PMID 37952131
  4. [4] Wilding JPH. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension (2022). PMID 35441470
  5. [5] FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (content current as of October 1, 2026) (2026). FDA
  6. [6] MedWatch: The FDA Safety Information and Adverse Event Reporting Program (2026). FDA

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