How to Report a GLP-1 Side Effect to FDA MedWatch, Step by Step

To report a suspected GLP-1 side effect to FDA, use MedWatch: go to FDA's online reporting page, choose the Consumer/Patient form (Form FDA 3500B), describe the product and what happened, and submit. You can also call 1-888-INFO-FDA (1-888-463-6332) and press 2 for reporting instructions, or fax a paper form. If you gather your details first, the whole thing goes quickly.

Before any of that, one rule: your health comes before the paperwork. A MedWatch report is not a way to get medical help.

When should you get care instead of filing a report?

• Emergency (trouble breathing, severe allergic reaction, severe or persistent belly pain, fainting): call 911. MedWatch's own reporting page says the same.
• Possible overdose or wrong amount: call Poison Control at 1-800-222-1222.
• Mental health crisis: call or text 988.
• Anything else worrying: contact your prescriber or pharmacist. Don't stop or change your dose on your own.

You can file a report later, once you're safe. FDA won't review it fast enough to help you that day, and MedWatch doesn't give medical advice.

What can you report to MedWatch?

MedWatch accepts reports about human medical products, including prescription drugs, for:

• Serious reactions or other adverse events you suspect are linked to the medicine
• Product quality problems (a pen that won't click, a cloudy solution, damaged packaging)
• Therapeutic failure (the product didn't seem to work as expected)
• Product use errors (wrong dose, mix-ups between products)

This applies to brand-name GLP-1s and to compounded versions. FDA specifically encourages patients and health professionals to report problems with compounded or unapproved GLP-1 drugs to MedWatch.

You don't need to be sure the medicine caused the problem. A report means "I suspect a link," which is exactly what FDA wants to hear about. (Why a report isn't proof is covered in our sibling post on adverse-event reports and causation.)

What should you gather before you start?

Have this ready and the form goes much faster. Copy the checklist:

Detail	Where to find it	Got it?
Product name and strength (brand or "compounded")	Pen, carton, pharmacy label	☐
Form (pen, vial, pill)	Packaging	☐
Lot number and expiration date	Pen label or carton	☐
Pharmacy name (especially if compounded)	Pharmacy label	☐
Date you started and dates of any dose changes	Your log or prescription history	☐
What happened, when it started, how long it lasted	Your notes	☐
What was done (ER visit, tests, stopped medicine) and the outcome	Visit summary	☐
Other medicines and supplements	Medication list	☐
Relevant health conditions, age, weight	You	☐

Keep the packaging and any leftover product in case anyone asks about it later. Don't mail medicine to FDA unless FDA asks.

If you already keep a side-effect log (in a notebook or an app like GLPily, where doses, symptoms and notes are dated), most of this list is already done. A medication list for urgent care covers the rest.

How do you file a MedWatch report online? (step by step)

1. Go to FDA's MedWatch online reporting page (search "MedWatch online reporting" or go to accessdata.fda.gov/scripts/MedWatch).
2. Under "Begin Online Report," choose Consumer/Patient. That opens the plain-language Form 3500B. (Health professionals use Form 3500.)
3. Describe the problem. What happened, when, how serious, and what was done about it. Plain words are fine; you don't need medical terms.
4. Describe the product. Name, strength, how you used it, dates, lot number. If it was compounded, say so and name the pharmacy.
5. Add details about the person affected. Age, sex, weight, relevant conditions, other medicines. You can report for a family member you care for.
6. Add your contact information. It's optional, but FDA encourages it so it can follow up. You can ask FDA not to release your contact details to the manufacturer.
7. Need a break? Save it. You'll get a Report ID. With that ID and the report date, you can come back and finish within 3 days of starting.
8. Review and submit.

Important: once submitted, a report can't be retrieved or edited. If you forgot something, start a new report and repeat the product, event summary, reporter and patient details along with the new information.

Prefer phone or paper?

• Phone: 1-888-INFO-FDA (1-888-463-6332), then press 2 for MedWatch reporting instructions.
• Paper: download Form FDA 3500B from FDA's MedWatch forms page and follow the instructions on it to mail or fax it. FDA lists its MedWatch fax number as 1-800-FDA-0178.
• Your clinician: a health professional can file a report or add clinical details from your records, but you don't need them to. You can report yourself.

What happens after you submit a MedWatch report?

Less drama than you might hope, more useful than you might think:

1. It goes into FDA's database. Since March 2026 that's the Adverse Event Monitoring System (AEMS), which replaced FAERS.
2. A safety evaluator reviews it, often a pharmacist, doctor or nurse, and compares it with similar reports.
3. FDA monitors trends and investigates when appropriate.
4. If a real problem emerges, possible actions include safety alerts, label updates, a Medication Guide, manufacturer inspections, design or packaging changes, recalls or further safety studies.

What usually doesn't happen: a personal ruling on whether the drug caused your problem, or medical advice. Your report becomes one data point among many. That sounds small, but FDA's own reporting page points out that a single report "may be the critical action that prompts a modification in use or design of the product."

Spot the trick

1. "I reported it to FDA, so I don't need to tell my doctor."

Show answer

Backwards. FDA uses reports for safety monitoring, not to treat you. Your prescriber or pharmacist needs to know, and should hear first.

2. "I'm not 100% sure the GLP-1 caused it, so I shouldn't report."

Show answer

Suspicion is enough. MedWatch is for suspected problems. Working out cause is FDA's job, using many reports and other data.

3. "Thousands of people reported this, so FDA must have confirmed it."

Show answer

Report counts are signals, not confirmations. FDA says the existence of a report does not establish causation. Look for what FDA actually concluded, for example in a safety communication. Our guide to reading an FDA safety alert helps.

Scoring: 3 out of 3 and you're ready to file a clean, useful report. FDA's safety evaluators thank you in advance.

Common questions

Can patients report side effects to FDA, or only doctors?

Patients and caregivers can report directly. MedWatch has a consumer form (Form FDA 3500B). A health professional can help, but doesn't have to.

Will FDA respond to my MedWatch report?

Don't expect a personal reply or medical advice. FDA uses reports to monitor safety across many people, and including your contact details lets it reach you if it needs more information.

Can I report a side effect from compounded semaglutide or tirzepatide?

Yes. FDA encourages reports about compounded and unapproved GLP-1 products. Include the pharmacy name and any label details you have.

Is my MedWatch report private?

Contact details are optional, and you can ask FDA not to release them to the manufacturer. FDA describes MedWatch reporting as confidential and secure.