19 Controversial Peptides Explained: Should You Be Taking These Amid Limited Safety Evidence?

Access rules are shifting

The FDA has considered removing some of 19 synthetic peptides from its Category 2 Bulk Substances List. That classification reflects significant safety concerns and bars compounding pharmacies from producing listed substances.

A panel voted to loosen restrictions on BPC-157, TB-500, KPV, MOTS-C, Epitalon and Semax. It voted against easing restrictions on Emedeltide, which people use in hopes of improving sleep. No compound received unanimous support.

In October, US Health Secretary Robert F. Kennedy Jr. advanced a policy temporarily expanding access to the six peptides. Under the policy, licensed compounding pharmacists with prescriptions would not face penalties for making and distributing them. Reactions to the move have varied.

Support and caution

Jeff Cohen, cofounder of the American Peptide Association, welcomed the administration’s action. He called it “much needed clarity” for the peptide industry, clinicians and consumers, in an email to MH.

Sritha Rajupet, MD, MPH, of Stony Brook Medicine, said most peptides still lack strong human evidence on safety, effectiveness and suitable doses. Removing a Category 2 designation would not resolve those research gaps. The policy document also requires compounding pharmacists to report serious adverse events and product-quality problems to the FDA and the states where products are made.

Kent Bradley, MD, chief medical officer at 10X Health, said some people seeking peptides have already tried conventional treatments. He also described cases in which people obtained products without legitimate pharmacy quality checks and used them based on social-media information. Rajupet said clinicians should discuss the therapies openly while explaining that their risks and benefits remain uncertain.

Evidence remains limited

The peptides under consideration are synthetic substances delivered by spray or injection. They are intended to trigger responses similar to those of natural peptides, but research is at an early stage. Reports of better health, appearance or muscle performance are anecdotal.

AOD-9604 is promoted as a fat-burning peptide. It mimics human growth hormone to encourage lipolysis, or the breakdown of stored fat, and has been studied as a possible obesity treatment. People also use it for body fat reduction, fat metabolism and body recomposition; claims about joint pain, mobility and collagen production have also circulated.