Stress Test: The Hidden History of a Peptide in FDA's Sights

This July 2026, an advisory committee for the U.S. Food and Drug Administration (FDA) will evaluate seven unapproved peptides to determine whether they should be available through specialized pharmacies. Over the decades, the FDA has regulated these kinds of substances as drugs, and their manufacturers have had to prove that the products are both safe and effective before putting them on the market. Health and Human Services Secretary Robert F. Kennedy Jr., and other key figures in the Make America Healthy Again (MAHA) movement, want to change this.

Among the peptides to be evaluated is BPC-157, a substance that can be traced back to a laboratory in the former Yugoslavia and to a Croatian researcher named Predrag Sikiric. Over the decades, his peptide has been studied by pharma companies, embraced by bodybuilders, and marketed by influencers. But it has yet to be fully vetted in the kind of rigorous human studies required for FDA approval. And the full history of the peptide’s development has not been written.

Sikiric has granted Undark access to his team in Zagreb, including extensive interviews with him, his collaborators, and more than 20 of his students. This story delves into the origins of BPC-157 and looks at what happened to the drug when it was licensed to a major pharmaceutical company. We also hear from outside experts in drug development and peptide research to better understand the data behind BPC-157 and what it means for patients in the U.S. who may soon have legal access to this substance.