Most Common Side Effects of Wegovy
Wegovy (semaglutide), used for weight management, commonly causes gastrointestinal issues. These affect over 5% of users in clinical trials and often occur during dose escalation.[1]
- Nausea (up to 44% of patients)
- Diarrhea (up to 30%)
- Vomiting (up to 24%)
- Constipation (up to 24%)
- Abdominal pain (up to 20%)
- Headache (up to 14%)
- Fatigue (up to 11%)
- Dyspepsia (indigestion, up to 9%)
- Dizziness (up to 8%)
- Bloating (up to 7%)
- Burping (up to 6%)
- Hypoglycemia (low blood sugar, up to 6% in non-diabetics)
Most are mild to moderate and decrease over time as the body adjusts.[1][2]
Why Do These Side Effects Happen?
Wegovy mimics GLP-1, a hormone that slows stomach emptying and signals fullness. This leads to GI upset, especially early on. Taking it with food or starting at low doses (0.25 mg weekly, ramping up) reduces nausea.[1]
How Long Do Side Effects Last?
They peak in the first 4-8 weeks during titration, then often fade. Persistent issues affect about 5-10% of users; switching to oral semaglutide (Rybelsus) sometimes helps if GI tolerance is poor.[2][3]
Serious but Less Common Risks
Beyond common effects, watch for:
- Gallbladder problems (cholecystitis, 1.6%)
- Pancreatitis (rare, <1%)
- Acute kidney injury from dehydration
- Thyroid tumors (boxed warning from rodent studies; human risk unclear)
- Allergic reactions or vision changes (diabetic retinopathy worsening)
Stop and seek medical help for severe pain, persistent vomiting, or yellowing skin.[1][4]
Tips Patients Use to Manage Nausea and GI Issues
- Eat smaller, bland meals; avoid fatty/spicy foods.
- Stay hydrated; ginger or anti-nausea meds like Zofran (if prescribed).
- Inject on an empty stomach at night.
- Over-the-counter remedies: Pepto-Bismol or probiotics for diarrhea/constipation.
About 16% discontinue due to side effects, mostly GI-related.[2]
Differences from Ozempic or Mounjaro Side Effects
Wegovy and Ozempic are the same drug (semaglutide) at different doses—similar profile, but Wegovy's higher dose (up to 2.4 mg) amps up GI effects. Mounjaro (tirzepatide) has comparable nausea (20-30%) but more diarrhea (20-25%) and less constipation.[3][5]
Sources
[1]: Wegovy Prescribing Information (Novo Nordisk)
[2]: FDA Label for Wegovy
[3]: NEJM STEP Trials on Semaglutide
[4]: Drugs.com Wegovy Side Effects
[5]: Mounjaro Prescribing Information (Eli Lilly)