The Peptide Craze Ground Truths Category 1 vs. Category 2. The FDA's peptide update, explained. Category 2 peptides are on the FDA's difficult to compound list, which effectively blocks licensed pharmacies from producing them. Category 1 means FDA takes first step in possible reversal of ban on some peptides The Washington Post What Peptides Are Legal in the U.S.? Understanding FDA Approval, Compounding, and the Legal Gray Areas Holt Law FDA puts some peptides off limits