This space has its own vocabulary, and a lot of it gets thrown around without explanation. Here’s a plain-language reference for the terms that come up most often across our content.
Sourcing & Quality Terms
COA (Certificate of Analysis): A lab document verifying a specific batch’s purity and composition. Should be batch-specific, not generic.
Research use only (RUO): A legal framing indicating a substance is sold for laboratory research purposes, not human consumption — a legal designation, not a purity or safety claim.
Lyophilized: Freeze-dried. Most peptides ship in this form and require reconstitution with a liquid before use.
Reconstitution: Mixing a lyophilized peptide with a liquid (typically bacteriostatic water) to create an injectable or usable solution.
Regulatory Terms
Category 1 / Category 2: An FDA classification of whether a nominated compounding substance is barred from consideration. Category 2 substances are effectively prohibited from compounding.
503A / 503B: Two types of compounding pharmacy designations. 503A compounds against individual patient prescriptions; 503B outsourcing facilities compound in larger batches under stricter standards.
PCAC: Pharmacy Compounding Advisory Committee, the FDA advisory body that recommends whether substances belong on the 503A bulks list.
Women’s Health-Specific Terms
PMOS: Polyendocrine Metabolic Ovarian Syndrome, the 2026 renaming of PCOS reflecting its metabolic-first framing.
HSDD: Hypoactive sexual desire disorder, the FDA-recognized condition PT-141 (bremelanotide) is approved to treat in premenopausal women.
Perimenopause: The transitional years leading up to menopause, typically marked by fluctuating rather than uniformly declining hormone levels.