epithalon vs ss-31

updated October 28, 2026

epithalon (tier C) vs ss-31 (tier A): what each is, why each got its grade, half-life and source counts side by side.

epithalon · tier C

russian longevity peptide. one lab. one cohort. the lifespan claims have never been replicated.

tier rationale

C-tier because the biology is plausible but the marketing has badly outrun the evidence. A real peptide from a real research program, with some mechanistic basis in pineal signaling and melatonin modulation. But the commercial sales pitch, telomerase activation and human lifespan extension, is the overreach. Single-lab data, single-cohort clinical trial, no Western replication. Community reports a sleep benefit that's probably real, but that's a much smaller claim than what vendors sell the compound on. Moves to B-tier only if independent replication of the telomerase or lifespan claims appears.

ss-31 · tier A

the first mitochondria-targeted peptide drug. FDA-approved september 2025. for Barth syndrome, studied for heart failure.

tier rationale

A-tier because SS-31 now has FDA approval (September 2025) for a specific rare disease, plus substantial phase 2/3 clinical trial data across multiple indications. Not S-tier because the approved indication is extremely narrow (Barth syndrome, <1,000 US patients) and the broader phase 3 programs in more common conditions (heart failure, mitochondrial myopathy) have been mixed. Comparable in structure to sermorelin's tier placement: FDA approval for a narrow indication with widespread off-label interest. If heart failure or aging trials read out positively in future years, moves to S.

at a glance

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.