PepEvolutionThymosin α-1
Zadaxin
A globally-approved immune-modulating peptide (Zadaxin) with a deep international evidence base and an exceptionally clean safety record.
Verdict — B · Viable
A standout among the immune/longevity peptides — real international approvals, a meaningful trial base, and a very clean safety profile. Held to a B mainly by the absence of US FDA approval and unverified sourcing rather than by any evidence or safety weakness. Source it verified.
Overview
Thymosin alpha-1 is a 28-amino-acid immunomodulatory peptide marketed as Zadaxin and approved in roughly 35 countries (though not by the US FDA) for hepatitis B and C, as a vaccine adjuvant, and as an adjunct in sepsis and certain cancers. It has one of the more substantial international clinical-trial bases of any non-FDA peptide and an exceptionally clean safety record across those trials. The main constraints for a US buyer are the lack of domestic approval and reliance on gray-market or international sourcing that is not COA-verified.
PepScore Breakdown — the four axes
Evidence
35% weightHow strong is the published human science?
Sourcing & COA
30% weightOur moatCan a buyer obtain an independently-verified, high-purity version? — our proprietary layer.
Safety & Risk
25% weightWhat is the real-world harm potential?
Practicality
10% weightHow easy is it to actually run a verified version?
Sources & Citations
Every claim cites a primary source. Citations are machine-audited against NCBI — see methodology.
Educational only — not medical advice. PepScore is an educational research grade, not a prescription or dosing recommendation. Some vendor links are affiliate links — this never affects grades. Consult a licensed healthcare provider before using any compound.