FDA Puts BPC 157, TB 500, and 5 Other Peptides Under the Microscope: What Prescribers Need to Know About the 503A Review Lengea FDA Removes 12 Peptides from 503A Category 2 Newtropin FDA Moves to Reevaluate Several Peptides American Med Spa Association Check out FDAs new roster of bulk drug substances being pulled from use in compounding. Youll see BPC 157 and TB 500 among the various peptides added to the list of category 2 substances