The FDA labels for Wegovy and Zepbound list nausea, vomiting, diarrhea, constipation and other adverse reactions. Gastrointestinal symptoms may occur during dose escalation and may improve over time, but some are severe or persistent. Treatment changes should be discussed with your prescriber rather than delayed in expectation of complete resolution.
GLP-1 medications significantly slow gastric emptying — how quickly food moves from your stomach to your intestines. This is part of how they create fullness, but it also causes the GI side effects. Your body adjusts over time, and for most patients, side effects diminish substantially after the initial adjustment period and between dose increases.
Side-by-Side Reference: Common Side Effects
Nausea
Common; see product labelManagement: Try smaller meals and eat slowly. Avoid foods that worsen your symptoms. Ask your provider about persistent nausea; do not adjust your dose independently.
Diarrhea
Common; see product labelManagement: Stay hydrated. Avoid high-fat and high-fiber foods temporarily. BRAT diet (bananas, rice, applesauce, toast) can help. Contact provider if severe or prolonged.
Constipation
Common; see product labelManagement: Maintain hydration appropriate to your medical needs, increase fiber as tolerated and discuss persistent symptoms or laxatives with your provider.
Vomiting
Common; see product labelManagement: Try small sips of fluid. Seek prompt care if you cannot keep fluids down or show signs of dehydration; do not wait a fixed number of hours.
Stomach discomfort / bloating
CommonManagement: Eat smaller, more frequent meals. Avoid carbonated drinks. Avoid eating too quickly. May improve after the first few weeks.
Fatigue
Reported by some patientsManagement: Ensure adequate protein and overall caloric intake. Avoid severe caloric restriction. If persistent, discuss with your provider.
Severe abdominal pain
RareManagement: Seek immediate medical attention. Severe or persistent abdominal pain can indicate pancreatitis, which requires immediate evaluation.
Gallbladder issues
Rare (slightly elevated vs baseline)Management: Report pain in the upper right abdomen, particularly after meals, to your provider. Gallstones are slightly more common during rapid weight loss.
The Golden Rules for Minimizing Side Effects
- Follow your prescribed titration schedule. Increasing doses more quickly than instructed can increase adverse-reaction risk.
- Eat small amounts throughout the day rather than large meals. Large meals overload a stomach that is already emptying more slowly.
- Avoid high-fat foods, especially in the first weeks. Fat slows gastric emptying further — and GLP-1 already slows it significantly.
- Follow product-specific injection instructions. Bedtime administration is not established as a way to prevent nausea.
- Maintain hydration according to your provider's advice. Needs differ, particularly with kidney or heart disease or a prescribed fluid restriction.
- Discuss alcohol with your provider; it can worsen symptoms and may affect blood sugar depending on your conditions and other medicines.
- If side effects are preventing normal functioning, call your provider before stopping medication. A dose reduction or slower titration schedule may resolve the issue without abandoning treatment.