Sources: U.S. Food and Drug Administration (FDA) Compounding and the FDA (503A & 503B guidance) FDA warning letters on unapproved peptide products National Institutes of Health (NIH) PubMed Think twice before injecting peptides bought online: unauthorized products can seriously harm you Canada.ca The U.S. Food and Drug Administration is moving toward allowing compounding pharmacies to produce more than a dozen injectable peptides that were banned because of potentially significant safety risks, the New York FDA moves toward easing restrictions on certain peptides BioPharma Dive