The Peptide Library

Peptides are short chains of amino acids — typically between 2 and 50. Your body produces thousands of them naturally. They act as signaling molecules, telling cells what to do: repair tissue, regulate appetite, modulate immune response, release growth hormone. The biology isn't new. The ability to use specific peptides therapeutically is what's changed.

Compounded peptides are prepared by licensed US pharmacies under a prescription from a licensed clinician. They are not the same as brand-name drugs — compounded medications are not FDA-approved, but they are legally prepared under FDA-regulated pharmacy compounding guidelines (503A and 503B). This is the same regulatory framework that has allowed pharmacies to compound custom medications for decades.

The FDA classifies bulk drug substances used in compounding into categories. Category 1 substances can be compounded today. Category 2 substances are under review and currently cannot be legally compounded. When the FDA changes a peptide's classification, the legal landscape shifts — and so does what your clinician can prescribe.