Start with what is not true
Nothing has been shown to extend human lifespan in a trial. Not a peptide, not a drug, not a supplement.
There is no approved treatment for ageing. Ageing is not a recognised indication a medicine can be approved for, which means no compound has ever had to prove anything against that standard.
Every longevity claim in this category is therefore an extrapolation — from a mechanism, an animal study, or a marker.
The compounds people mean
Epitalon is the most direct. It is sold explicitly on ageing, supported by published cell and animal work reporting telomerase activation and telomere lengthening. Two caveats belong with that: the research is dominated by the group that originated the compound, and recent work reports lengthening in cancer cells as well as normal ones. Telomere shortening is partly how the body limits cells that should stop dividing.
MOTS-c and SS-31 relate to mitochondria, and this is the more serious end. Mitochondrial decline is a genuine feature of ageing. SS-31 (elamipretide) reached real clinical trials — but in rare genetic mitochondrial disease, where the machinery is measurably broken from birth. Restoring a failing system is a different proposition from improving a working one, and the second has not been studied.
5-Amino-1MQ is included in longevity discussions because it touches NAD+ handling. It is not a peptide — it is a small-molecule enzyme inhibitor — and its evidence is cells and mice.
Thymalin and related preparations come from the same Russian research tradition as epitalon, with the same concentration of evidence in the originating institution.
The same St Petersburg programme produced a family of very short peptides beyond epitalon, each assigned to a tissue. The one assigned to cartilage — shows how thin those files can be: six published papers, every one of them in cell culture. Thymalin, the thymus preparation from the same institute, carries the tradition's largest human literature and the claim that it lengthens life.
The measurement problem
Longevity is unusually hard to study, and the difficulty is structural rather than anyone's fault.
The outcome takes decades. No trial can wait, so trials use markers instead: telomere length, a mitochondrial measure, an inflammation number. Then a marker moves, and the marker is reported as the result.
A marker moving is not the outcome. The history of medicine contains a long list of markers that moved convincingly while the thing that mattered did not follow — and several where the intervention that moved the marker turned out to cause harm.
This is not an argument that the field is worthless. It is the reason its evidence will remain indirect for a long time, and the reason confident claims in this area should be read with more suspicion than confident claims about, say, wound healing.
What each entry says
- Epitalon — the telomere peptide, and who did the research
- MOTS-c — a mitochondrial-derived peptide
- SS-31 — elamipretide, the one that reached real trials
- 5-Amino-1MQ — not a peptide, and what that changes
- What are peptides — if any of the above was unfamiliar
One more compound belongs in this discussion and is easy to misread: the mitochondrial peptide humanin has 542 published papers and seven trial registrations, and every one of those registrations measures the peptide the body already makes rather than giving any.
Entries for every compound named here, and for the ones that are not, sit in the alphabetical compound index.
Last checked
2026-09-07.
