Injectable Peptides: Out of the Back Alley and Into the Light? Berkley Lifesciences FDA Warning Letter to Neil R. Feins, M.D. 2009 05 20 Circare The FDA will hold a meeting to consider easing restrictions on more than a half dozen peptide injections, a group of unapproved therapies that have become popular among wellness influencers, fitness gurus The FDA has issued warning letters to multiple companies marketing compounded Retatrutide, an investigational drug from Eli Lilly still in Phase II trials. While early studies have shown promising weight loss results, Retatrutide Heard about BPC 157 in health and wellness products? Think it's a "miracle" peptide? Think again. Claims about BPC 157 are based on lab or animal studies, NOT human clinical studies.