How do I report a side effect to the FDA?
Report a suspected side effect of a GLP-1 such as Wegovy, Ozempic (semaglutide), Zepbound or Mounjaro (tirzepatide) to the FDA’s MedWatch program, online through its Report a Problem form or on 1-800-FDA-1088, the number in each US Medication Guide. Patients and caregivers can report directly, using the consumer form 3500B.
How do you report to MedWatch?
There are 3 ways: the online form, a paper form you download and send in, or a phone call.1,2
- Online: MedWatch’s “Report a Problem” form on fda.gov.1
- On paper: Form FDA 3500B, written for consumers, which you download, fill in and send to MedWatch.2 The FDA’s counterfeit warning gives the MedWatch fax number, 1-800-FDA-0178.5
- By phone: the Wegovy and Zepbound Medication Guides say “You may report side effects to FDA at 1-800-FDA-1088.”3,4 The FDA’s reporting page also lists 1-888-INFO-FDA (1-888-463-6332).2
You can also tell the maker. The labels list Novo Nordisk on 1-833-934-6891 for Wegovy and Eli Lilly on 1-800-545-5979 for Zepbound.3,4
What can you report?
MedWatch takes reports of serious reactions, product quality problems, product use errors and medicines that didn’t work as expected.2
That covers suspected fakes too. The FDA asks people to report problems with counterfeit Ozempic through MedWatch.5 Problems with compounded semaglutide or tirzepatide count as well; the FDA tracks those reports and had 990 for compounded semaglutide by May 31, 2026.6
Keep the box or pen if you can, since the lot number helps. The FDA’s counterfeit warnings identify fakes by lot number.5
Should your doctor report it instead?
Either of you can. The FDA encourages you to share the form with your doctor, but says “your health care provider is NOT required to report.”2
Reporting doesn’t replace care. The Medication Guides say to call your doctor for medical advice about side effects, and that you may also report them to the FDA.3,4 For urgent symptoms, see When should I call 911 on a GLP-1?
Common side effects and what helps are in Guide 5.
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Related questions
Sources
- FDA. MedWatch: the FDA safety information and adverse event reporting program (“Report a Problem”). Content current as of Oct 9, 2026. fda.gov
- FDA. Reporting serious problems to FDA: online form, Form FDA 3500B for consumers, 1-888-INFO-FDA. Content current as of Sep 26, 2025. fda.gov
- Novo Nordisk. Wegovy (semaglutide) injection and tablets, US prescribing information and Medication Guide, revised 06/2026. US label. novo-pi.com
- Eli Lilly. Zepbound (tirzepatide) US prescribing information, Medication Guide and Instructions for Use, revised 08/2026. US label. uspl.lilly.com
- FDA. FDA warns consumers not to use counterfeit Ozempic (semaglutide) found in U.S. drug supply chain (warnings of Dec 21, 2023, Apr 14, 2025, and Dec 5, 2025). Content current as of Dec 5, 2025. fda.gov
- FDA. FDA’s concerns with unapproved GLP-1 drugs used for weight loss. Content current as of Oct 1, 2026 (adverse-event counts as of May 31, 2026). fda.gov
Last checked Oct 12, 2026 · Next review due Oct 12, 2027 · Report an error
How this answer was made. Written by the GLP Guidebook team from the sources above, all checked on Oct 12, 2026. It’s general information, not medical advice. Talk to a doctor, pharmacist or other licensed prescriber before starting, stopping or changing any medicine. In an emergency, call 911. How we write