Why is the FDA regulating peptides like BPC-157?

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

Why are some peptides getting the side-eye from the FDA?

If you have been following the news lately, you might have noticed the FDA is becoming a bit more protective of the peptide world. As of March 2026, several popular substances have been moved into what the FDA calls Category 2.

In plain English, this means the FDA believes these substances pose a significant safety risk and are not eligible for routine compounding—which is when a pharmacy custom-mixes a medication for you.

Which ones are on the list?

Several well-known peptides are currently facing strict regulatory hurdles. Here is the breakdown of what the FDA is saying:

BPC-157: This is currently a Category 2 substance. The FDA has concerns about immunogenicity—which is when your body’s immune system has an unwanted reaction to a drug—and a general lack of safety data.
CJC-1295: This was removed from the nomination list in September 2024. The FDA cited safety issues including an increased heart rate.
TB-500: Listed in Category 2 because of risks like immunogenicity and a total lack of data regarding how it affects humans.
GHK-Cu: Even though it is popular, the FDA notes this is not an approved injectable drug and carries immunogenicity risks.
Thymosin Alpha-1: While it is approved in over 35 countries under the name Zadaxin, it is not FDA-approved in the US and is still viewed as a substance of concern.

What about warning letters?

The government does not just make lists; they also send mail. In 2020, a company called Tailor Made Compounding received warning letters covering a huge range of peptides, including AOD-9604, Ipamorelin, Selank, Semax, and GHRP-2. If you see these being sold, it is worth remembering that none of them are currently FDA-approved.

Safety signals you should know about

When a drug is widely used, the FDA tracks adverse events, which is just a formal way of saying side effects. Semaglutide has a lot of data because so many people use it.

Some common issues found in the records include:

Gastrointestinal problems: Nausea and vomiting are very common and usually managed by slowly increasing the dose.
Delayed Gastric Emptying: This means food stays in your stomach longer, which can affect how you absorb other pills or cause issues during surgery.
Gallbladder issues: Problems like gallstones have been linked to the rapid weight loss people experience on this medication.
Newer Concerns: There are emerging signals for things like intestinal obstruction (a blockage in the gut) and even pulmonary aspiration, which is a risk when undergoing general anesthesia.

The bottom line on research

Scientists are still working on this—turns out the human body is complicated. Who knew? While Tirzepatide and Semaglutide have completed large Phase III trials showing significant weight loss, others are still a mystery. For example, a Phase III trial for Thymosin Alpha-1 regarding sepsis actually came back negative, showing no reduction in mortality.

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