Optimum Formula

Optimum Formula is a US-based research-peptide supplier with one of the strongest verified COA programs we track: public, batch-linked third-party certificates from two named labs — Kovera Labs (a full panel of HPLC purity, LC-MS identity, endotoxin, microbial sterility, and 3-vial batch conformity, verifiable at koveralabs.com/verify) and Vanguard Laboratory (ISO/IEC 17025:2017, A2LA-accredited — HPLC purity/quantity plus LAL endotoxin).

That named, accredited, batch-level testing is exactly what our 40% COA factor rewards most, and we confirmed it from real sample certificates. The remaining gap is reputation, not testing: there's no dedicated Trustpilot page and the independent Reddit/forum footprint is thin, which is what keeps the overall score from going higher. US-based; 10%-off reader code. Prices in USD.