Understanding GLP-1 Side Effects: What to Expect
Affiliate Disclosure: We earn commissions when you sign up through our links. This doesn't affect our rankings. Learn more·For informational purposes only—not medical advice.
GLP-1 medications like semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro) are effective weight loss treatments, but like all medications, they come with potential side effects. Understanding what to expect helps you prepare and know when to seek medical attention.
Medical Disclaimer
This information is educational only. Always discuss side effects with your prescribing physician. Do not stop or change your medication without medical guidance.
Common Side Effects
The most frequently reported side effects are gastrointestinal in nature. According to FDA prescribing information, these occur in more than 5% of patients:
Gastrointestinal Effects
- Nausea - Most common, especially during dose increases
- Diarrhea - Often temporary, improves with time
- Constipation - May require dietary adjustments
- Vomiting - Usually related to eating too quickly or too much
- Abdominal pain - Typically mild to moderate
Quick Facts
- Most common side effect
- Nausea (40-50% of patients)
- Typical improvement timeframe
- 4-8 weeks
- Dose-related
- Yes, often worse at higher doses
- Reason for discontinuation
- ~5-7% in clinical trials
Serious Warnings
While rare, some side effects require immediate medical attention.
Seek Immediate Care If You Experience
- Severe abdominal pain that doesn't go away
- Signs of pancreatitis (persistent severe pain radiating to back)
- Signs of allergic reaction (swelling, difficulty breathing)
- Symptoms of thyroid tumors (lump in neck, hoarseness, difficulty swallowing)
- Severe hypoglycemia if also taking insulin
Boxed Warning: Thyroid C-Cell Tumors
GLP-1 medications carry an FDA boxed warning about thyroid C-cell tumors observed in rodent studies. While this hasn't been confirmed in humans, these medications are contraindicated in patients with:
- Personal or family history of medullary thyroid carcinoma (MTC)
- Multiple Endocrine Neoplasia syndrome type 2 (MEN2)
Managing Side Effects
Most side effects can be minimized with proper strategies:
Eating Strategies
- Eat smaller portions - Your appetite is reduced; honor that signal
- Eat slowly - Take 20+ minutes for meals
- Avoid high-fat foods - These can worsen nausea
- Stay hydrated - Sip water throughout the day
- Stop eating when satisfied - Not when full
Lifestyle Adjustments
- Don't lie down immediately after eating
- Avoid alcohol - Can worsen GI symptoms
- Consider ginger tea - May help with nausea
- Walk after meals - Aids digestion
Titration Strategy
The standard approach is to start at a low dose and increase gradually. This "slow and low" method significantly reduces side effects. If you're struggling, ask your provider about staying at a lower dose longer before increasing.
When to Contact Your Doctor
Contact your prescriber if you experience:
- Side effects that don't improve after 2-3 weeks
- Inability to eat or drink due to nausea
- Signs of dehydration
- Severe or worsening symptoms
- Any symptoms you're concerned about
Your provider may adjust your dose, extend your titration schedule, or prescribe supportive medications to help manage side effects.
This content is based on FDA prescribing information and clinical trial data. Individual experiences may vary. Always consult your healthcare provider with questions about your specific situation.
Frequently Asked Questions
Affiliate Disclosure: We earn commissions when you sign up through our links. This doesn't affect our rankings. Learn more