Wegovy is semaglutide, the same molecule as Ozempic, under a label covering weight management, cardiovascular risk reduction and a specific MASH population. 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.
| Outcome | Wegovy 2.4 mg | Placebo | Source |
|---|---|---|---|
| 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 effects | 6.8% | 3.2% | Label, weight trials [1] |
| Any digestive side effect | 73% | 47% | Label [1] |
| Severe digestive side effects | 4.1% | 0.9% | Label [1] |
| Gallstones (cholelithiasis) | 1.6% | 0.7% | Label [1] |
| Gallbladder inflammation (cholecystitis) | 0.6% | 0.2% | Label [1] |
| Acute kidney injury | 0.4 per 100 patient years | 0.2 per 100 patient years | Label [1] |
| Low blood pressure | 1.3% | 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.
Other warnings have different frequencies and clinical importance
Beyond the thyroid warning, Wegovy's label lists ten more, numbered 5.2 to 5.11 [1]. Frequency varies by warning and patient population; not every risk has a known rate. Here is 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. Concomitant insulin or a sulfonylurea can increase the risk; hypoglycemia can also occur without those medicines.
- 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]. For weight or cardiovascular use, the label recommends stopping at least 2 months before a planned pregnancy. For MASH, its pregnancy guidance instead requires an individual assessment of potential benefit and fetal risk; the prescriber should resolve that specific situation.
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. The reason a symptom is absent cannot be determined from that absence. An unlisted symptom can still require assessment.
| Symptom | In the label? | What the label says |
|---|---|---|
| Hair loss | Yes | 3% vs 1% on placebo with the 2.4 mg injection; linked to weight reduction |
| Injection-site reactions | Yes | 1.4% vs 1% on placebo (itching, redness, irritation) |
| Tiredness | Yes | Fatigue 11% vs 5% |
| Headache | Yes | 14% vs 10% |
| Dizziness | Yes | 8% vs 4%; low blood pressure 1.3% vs 0.4% |
| Urinary tract infection | Only in teens | 4% vs 2% in the trial of children 12 and older; not listed for adults |
| Joint pain, back pain, leg cramps, body aches | No | Not listed |
| Blood clots, chest pain | No | Not listed |
| Low sex drive, acne, hot flashes, migraines, brain fog, vertigo | No | Not listed |
| Blood in your stool | No | Not listed; see a clinician promptly, whatever the cause |
| Can it cause diabetes? | Not listed as an adverse reaction | The drug lowers blood glucose, but that does not settle the cause of a new glucose change; discuss it with the prescriber |
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]. Those adverse-event reports do not identify the cause of an individual’s pain or measure every brief needle sensation.
An extension study found substantial average weight regain
Discuss stopping with the prescriber, since weight and other clinical measures can change after treatment ends. 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 toward baseline. This was an exploratory 327-person subset, and both study medication and lifestyle intervention stopped; it cannot isolate every cause of regain or predict an individual’s course.
Hunger has several possible explanations. The Medication Guide includes hunger among low-blood-sugar symptoms, especially when accompanied by shakiness, sweating or confusion. Ask the prescriber about a new change rather than using hunger alone to judge treatment response. 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.