Wegovy Side Effects: What to Expect
Every reaction the semaglutide trial program recorded, alongside the boxed warning and the Section 5 risks its FDA label carries.
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Most Common Wegovy Side Effects
Every reaction the Wegovy FDA label records, showing how often it appeared among semaglutide-treated patients and how often it appeared on placebo. The figures are taken from the label's Section 6, DailyMed SetIDee06186f-2aa3-4990-a760-757579d8f77b.
| Adverse reaction | Incidence (Wegovy vs placebo) |
|---|---|
| Nausea | 44% (placebo 16%) |
| Diarrhea | 30% (placebo 16%) |
| Vomiting | 24% (placebo 6%) |
| Constipation | 24% (placebo 11%) |
| Abdominal pain | 20% (placebo 10%) |
| Headache | 14% (placebo 10%) |
| Fatigue | 11% (placebo 5%) |
| Dyspepsia | 9% (placebo 3%) |
| Dizziness | 8% (placebo 4%) |
| Abdominal distension | 7% (placebo 5%) |
| Eructation (burping) | 7% (placebo <1%) |
| Hypoglycemia (in patients with type 2 diabetes) | 6% (placebo 2%) |
| Flatulence | 6% (placebo 4%) |
| Gastroenteritis | 6% (placebo 4%) |
| Gastroesophageal reflux disease (GERD) | 5% (placebo 3%) |
| Gastritis | 4% (placebo 1%) |
| Gastroenteritis viral | 4% (placebo 3%) |
| Hair loss | 3% (placebo 1%) |
| Dysesthesia | 2% (placebo 1%) |
Source: Wegovy FDA prescribing information via DailyMed (SetID ee06186f-2aa3-4990-a760-757579d8f77b), Section 6 Adverse Reactions, read on 2026-05-31. Treat this as a summary — the full label is the document, and a prescriber is the person to discuss it with.
Boxed Warning — Thyroid C-Cell Tumors
“In rodents, semaglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether WEGOVY 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. WEGOVY is contraindicated in patients with a personal or family history of MTC or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).”
Quoted word for word from the Wegovy FDA label (DailyMed SetID ee06186f-2aa3-4990-a760-757579d8f77b). Nothing the FDA issues carries more weight than a boxed warning. Your own history and your family's both need to be on the table before you start Wegovy, and that means talking to a licensed prescriber.
Serious Warnings & Precautions
Past the everyday reactions above, Section 5 of the Wegovy label sets out these serious risks. They arrive far less often, and some of them need care the same day — which is why the symptoms are worth knowing and when to seek care.
- Risk of thyroid C-cell tumors
- Acute pancreatitis
- Acute gallbladder disease
- Hypoglycemia
- Acute kidney injury due to volume depletion
- Severe gastrointestinal adverse reactions
- Hypersensitivity reactions
- Diabetic retinopathy complications in patients with type 2 diabetes
- Heart rate increase
- Pulmonary aspiration during general anesthesia or deep sedation
Compare every Wegovy provider
Every warning above is something a prescriber screens for before writing anything. Current price, verification status, product form and the states each seller ships to are all on one screen.
Related deep-dives
What to do about each symptom, and the evidence underneath it, is covered here:
- How long GLP-1 side effects last →
- Hair loss and muscle loss on a GLP-1 →
- Pancreatitis and gallbladder risk →
- What the thyroid cancer warning rests on →
- Eye risk: NAION and retinopathy →
- Drinking on a GLP-1 →
- What happens when you stop →
- Where to inject, and why the site matters →
- Compounded semaglutide against the brand →
- GLP-1s, pregnancy and trying to conceive →