Why is the FDA banning or flagging certain peptides?

What is going on with the FDA and peptides?

You might have noticed that some peptides are getting a lot more attention from regulators lately. As of March 2026, the FDA (the government agency that oversees drug safety) has not approved many of the popular compounds people talk about. In fact, many have been placed into Category 2, which means the agency believes they pose a significant safety risk and shouldn't be routinely made by specialty pharmacies.

The peptides on the watch list

It turns out the human body is complicated, and the FDA is flagging several peptides due to a lack of safety data or specific side effect risks.

• BPC-157: This is currently listed as a Category 2 substance because of concerns about immunogenicity—which is just a fancy way of saying it might cause your immune system to overreact. It also lacks enough safety data for the FDA to feel comfortable.
• CJC-1295: This one was removed from the list of substances that pharmacies can easily make. The FDA noted safety issues, including an increased heart rate.
• TB-500: Regulators have flagged this for immunogenicity risks and a complete lack of data on how it affects humans.
• GHK-Cu: While often discussed, this is not an FDA-approved injectable drug and carries its own risks of immune system reactions.

Are there actual warnings?

Yes. Several companies have received official warning letters from the FDA. For example, a company called Tailor Made Compounding was issued a warning letter in 2020 regarding several substances, including AOD-9604, Ipamorelin, Selank, and Semax.

What about the peptides that are approved?

Even when a drug is approved, the safety monitoring never really stops. Take Semaglutide, for instance. While it showed a 14.9% weight loss in the STEP 1 clinical trial, real-world monitoring (called FAERS) has picked up several side effects that were later added to its official warning label:

• Nausea and Vomiting: Very common and usually managed by slowly increasing the dose.
• Delayed Gastric Emptying: This means food stays in your stomach longer, which can be a problem if you need surgery.
• Intestinal Obstruction: A newer signal that was added to the label after the drug was already on the market.
• Pancreatitis: A moderate signal for inflammation of the pancreas.
• NAION: This is a rare eye condition currently under review by European regulators as of January 2025.

Why do some countries allow these and we don't?

Regulatory agencies in different countries don't always agree. Thymosin Alpha-1 is approved in over 35 countries, but the FDA still considers it a "substance of concern." Similarly, Selank and Semax are approved in Russia, but they remain unapproved and restricted in the United States.

This is a great one to bring up with your doctor. You can find peptide-experienced physicians in our Find a Doctor directory.

This content is sourced exclusively from TruthTides clinical reference data and does not constitute medical advice.