Safety
Fake and compounded GLP-1 drugs in the US: what the FDA has warned about
Demand for semaglutide and tirzepatide created a parallel market of counterfeit pens, compounded copies and “research use only” vials. The FDA has issued alerts, warning letters and policy changes on each. This is a plain summary of what the agency has said, with links to every notice.
By the RetaRadar editors · Published October 1, 2026
Three different problems
People often lump these together, but the FDA treats them differently:
- Counterfeits are fakes made to look like a branded product such as Ozempic. They are illegal in every case.
- Compounded drugs are made by licensed pharmacies or outsourcing facilities for individual patients. They are legal within limits, but they are not FDA-approved, and the limits tightened once the shortages ended.
- “Research use only” products are peptides sold as laboratory chemicals. When they are marketed to people for weight loss, the FDA treats them as unapproved drugs.
Counterfeit Ozempic in the US supply chain
The FDA has found counterfeit Ozempic (semaglutide) in the legitimate US drug supply more than once (FDA counterfeit Ozempic alert, updated December 5, 2025):
| When | What was found |
|---|---|
| December 2023 | Counterfeit pens with lot number NAR0074; the needles were also fake, raising an infection risk. |
| April 2025 | Counterfeit pens with lot number PAR0362 and serial numbers starting 51746517. |
| December 2025 | “Dozens of units” of counterfeit Ozempic 1 mg seized, using lot number PAR1229 — a real lot number, so the lot alone does not prove a pen is genuine. |
The FDA’s advice is to buy GLP-1 medicines only with a prescription, from a state-licensed pharmacy, and to report suspected fakes to MedWatch.
Compounded semaglutide and tirzepatide
Why compounding grew — and why it is shrinking
While semaglutide and tirzepatide were on the FDA’s drug shortage list, compounders were allowed to make copies. The FDA declared the tirzepatide shortage resolved on December 19, 2024 and the semaglutide shortage on February 21, 2025. Grace periods followed: for tirzepatide they ended on February 18, 2025 (503A pharmacies) and March 19, 2025 (503B outsourcing facilities); for semaglutide on April 22 and May 22, 2025 (FDA compounding policy page).
Since then the FDA has moved further:
- September 2025: a “green list” import alert, under which GLP-1 ingredients from facilities the FDA has not evaluated can be detained at the border (FDA), and a crackdown on misleading drug advertising, including telehealth firms selling compounded GLP-1s (FDA).
- February 6, 2026: the FDA said it intends to act against non-approved GLP-1 drugs, including restricting the ingredients used to make them, and that firms may not claim a compounded drug is the same as, or a generic of, an approved one (FDA).
- March 3, 2026: warning letters to 30 telehealth companies over the marketing of compounded GLP-1s (FDA).
- April 30, 2026: a proposal to exclude semaglutide, tirzepatide and liraglutide from the list of substances outsourcing facilities may use, on the grounds that there is no clinical need (FDA). The comment period closed on June 29, 2026.
Adverse events and dosing errors
As of May 31, 2026, the FDA had received 990 adverse event reports involving compounded semaglutide and more than 730 involving compounded tirzepatide. The agency notes that a report does not prove the drug caused the problem (FDA’s concerns with unapproved GLP-1 drugs).
A specific risk is measurement. In July 2024 the FDA reported patients who had drawn 5 to 20 times the intended amount from multi-dose vials, often because of confusion between milliliters, milligrams and syringe “units”. Some were hospitalized with severe nausea and vomiting, fainting, dehydration, pancreatitis or gallstones (FDA dosing-error alert). The FDA also warns that salt forms such as semaglutide sodium and semaglutide acetate are not the same ingredient as in approved products.
“Research use only” peptides
A third market sells semaglutide, tirzepatide and investigational drugs such as retatrutide as laboratory chemicals. The FDA has said these labels do not protect sellers whose websites market the products to people. It has sent warning letters naming retatrutide to Summit Research Peptides (December 2024), ASN-LABS (September 2025) and Gram Peptides (March 2026). Retatrutide in particular cannot be compounded at all, because it is not part of any approved drug. Our retatrutide guide covers its trials and status.
This is one reason our listing rules exclude research sellers that publish dosing charts or dose calculators: those pages are exactly what the FDA cites when it says a product is really being sold for human use.
How to recognize a legitimate pharmacy
The FDA’s BeSafeRx campaign lists the basics. A safe online pharmacy (BeSafeRx):
- requires a valid prescription;
- has a US street address and phone number;
- has a licensed pharmacist available to answer questions;
- is licensed by the board of pharmacy in your state, which you can check on the board’s website.
Very low prices, no prescription, payment only in crypto or by gift card, and shipping from abroad are warning signs. For legitimate ways to lower the cost of approved drugs, see Zepbound vs Wegovy: cost and insurance coverage.
Labels are changing too
Not every FDA action has been a warning. On January 13, 2026, after reviewing 91 trials and a Sentinel cohort of 2.2 million people, the FDA asked the makers of Saxenda, Wegovy and Zepbound to remove the suicidal-behavior warning from their labels (FDA drug safety communication). That applies to the approved products only.