How to report a side effect to the FDA (MedWatch)

Updated 2026-10-08 · Reviewed for accuracy by the EKO Labs team. Educational only; not medical advice.

If you think a medicine caused a side effect, or you notice a problem with the product itself, you can tell the U.S. Food and Drug Administration (FDA). FDA's voluntary reporting program is called MedWatch. Patients, family members and caregivers can report directly; you do not need a doctor to do it. This guide explains how. It is general information, not medical advice.

In an emergency, call 911. If someone may have taken too much of a medicine or the wrong medicine, call Poison Help at 1-800-222-1222. A report to FDA does not get you medical care, so always tell your prescriber or pharmacist about a side effect too.

What you can report

• Side effects (adverse events), especially serious ones
• Product quality problems, such as a package or vial that looks damaged, cloudy, discolored or contaminated, or a labelPrescribing information (label) the official FDA document for a medicine, with its uses, warnings and side effects. that looks wrong
• A medicine that did not seem to work as expected, for example after a switch to a different product
• Medication errors, such as a mix-up caused by similar names or a confusing label

MedWatch covers prescription and over-the-counter medicines, biologics, medical devices, dietary supplements, infant formula and cosmetics. FDA also encourages patients to report adverse events and quality problems with compounded medicines. Problems after a vaccine go to a different system, VAERS (vaers.hhs.gov).

What FDA considers serious

FDA asks you to report an event as serious when you suspect it led to:

• death
• a life-threatening situation
• a hospital stay, or a longer hospital stay
• disability or permanent damage that seriously disrupts normal daily life
• a birth defect, after exposure before or during pregnancy
• the need for medical or surgical treatment to prevent permanent damage (for medical devices)
• another important medical event that may put the person at risk and need treatment to prevent one of the outcomes above

You can also report problems that are not serious, but serious events are the most important ones to send.

How to report

• Online: use the MedWatch online voluntary reporting form (fda.gov/medwatch).
• Paper form: download Form FDA 3500B, the consumer version of the form. A Spanish version is also available. Follow the instructions on the form to send it by mail or fax.
• Phone: call 1-888-INFO-FDA (1-888-463-6332) and press 2 to report to MedWatch or get instructions.

Health care professionals usually use Form FDA 3500. Your doctor or pharmacist is not required to report for you, so if you want FDA to know, you can send the report yourself.

What to include

• What happened, when it started, how long it lasted and what treatment was needed
• The age, sex and weight of the person who had the problem, and relevant health conditions or allergies
• The product name exactly as it appears on the label, the manufacturer or pharmacy, and the lot number and expiration date if you have them
• Whether the product was brand-name, generic or compounded, and where it came from
• Other medicines and supplements taken at the same time
• Relevant test results, if you have them

Keep the package, the label and any product that is left until you know whether anyone needs to see them. Clear photos of the label and the lot number help.

What happens to your report

Reports about medicines and biologics go into the FDA Adverse Event Reporting System (FAERS), which FDA uses to watch the safety of products after they are on the market. Many reports together can help FDA find a new safety problem.

One report does not prove that a medicine caused the problem. FDA explains that for any single report there is no certainty that the suspected drug caused the event, and that some reports are duplicates or incomplete. That is why clear details matter.

Your privacy

Under federal rules, FDA and manufacturers must not disclose the names or other information that would identify a voluntary reporter or the patient in an adverse event report, except in limited cases such as written consent. The person who is the subject of a report can ask for a copy of it.

Also tell

• Your prescriber, who can decide whether your treatment should change. Ask before you stop or change a prescribed medicine.
• The pharmacy that filled the prescription, especially for a product quality problem
• The manufacturer, if you wish; its contact information is usually on the label or the package insert

At EKO Labs, our team can answer your questions in Portuguese or English by phone. If you have a side effect with a treatment prescribed through EKO, tell our team and your prescriber.

Sources: FDA, Reporting Serious Problems to FDA (MedWatch); FDA, What is a Serious Adverse Event?; FDA, MedWatch Forms for FDA Safety Reporting (Forms 3500 and 3500B, Spanish consumer form); FDA, FAERS Public Dashboard (existence of a report does not establish causation); FDA, FDA's concerns with unapproved GLP-1GLP-1 (glucagon-like peptide-1) a hormone the gut releases after eating. It helps release insulin, slows stomach emptying and signals fullness. drugs used for weight loss; 21 CFR 20.63(f) (confidentiality of reporter and patient identities); VAERS (vaers.hhs.gov); Poison Help line (poison.org). This guide is general information, not medical or legal advice.