Epitalon vs Humanin
Two foundational longevity peptides with very different origins — a synthetic pineal tetrapeptide developed in the St Petersburg cytomedine programme, versus a mitochondrially-derived peptide discovered in surviving neurons from an Alzheimer's brain.
Epitalon (AEDG)
A synthetic tetrapeptide (Ala-Glu-Asp-Gly) derived from the pineal polypeptide epithalamin, studied for its effects on telomerase activity, circadian regulation, and lifespan extension in animal models.
Humanin (HN)
A 24-amino-acid mitochondrially-derived peptide encoded within the 16S rRNA gene, studied for cytoprotective, metabolic and neuroprotective signalling that declines with age.
Origin and structure
Epitalon is a rationally designed 4-amino-acid synthetic peptide (Ala-Glu-Asp-Gly) developed by Khavinson's group in the late 1980s as a synthetic equivalent of the active fraction of the pineal polypeptide epithalamin. It is chemically minimal — small enough to be hypothesised to reach the nucleus intact and bind DNA at specific motifs.
Humanin is a 24-amino-acid peptide encoded within the mitochondrial 16S ribosomal RNA gene — one of the first identified mitochondrially-derived peptides (MDPs). It was discovered in 2001 in surviving neurons from the occipital cortex of an Alzheimer's patient and is endogenously expressed in multiple human tissues.
Mechanism
Epitalon's reported activity centres on telomerase induction in cultured somatic cells and restoration of age-related declines in pineal-axis biomarkers. The proposed mechanism is direct DNA binding at promoter motifs, a model that remains the most contested aspect of the broader Khavinson short-peptide programme.
Humanin acts through both an extracellular G-protein-coupled receptor complex (FPRL1/CNTFR/WSX-1) and direct intracellular interactions with pro-apoptotic Bax. Its activity is cytoprotective and metabolic — it sensitises tissues to insulin, blocks apoptosis under stress, and circulates in plasma at levels that decline with age.
Evidence base
Epitalon has roughly 30 years of preclinical data, largely from the Khavinson research group, including reported lifespan extension and reduced spontaneous tumour incidence in CBA mice. Independent replication outside the original group is comparatively limited.
Humanin is more deeply embedded in international peer-reviewed literature, with substantial work from multiple independent groups (Cohen, Barzilai, Hashimoto, Nishimoto) and consistent findings on plasma decline with age and preservation in centenarian offspring.
Research positioning
Epitalon is studied as a probe of the telomerase-induction and pineal-axis hypotheses in ageing. Humanin is studied as a circulating mitokine and a candidate stress-response signal central to inter-organellar ageing biology. They are not interchangeable; the choice between them in any research protocol depends on the mechanism being probed.
Summary table
| Attribute | Epitalon | Humanin |
|---|---|---|
| Origin | Synthetic; designed from pineal polypeptide | Endogenous; mitochondrial 16S rRNA gene |
| Length | 4 amino acids | 24 amino acids |
| Primary mechanism | Proposed gene regulation, telomerase induction | Receptor-mediated cytoprotection + Bax binding |
| Decline with age | Pineal output declines; Epitalon proposed as restorative | Plasma Humanin falls ~30% age 30→70 |
| Independent replication | Limited outside original group | Substantial; multiple international groups |
| UK regulatory status | Not licensed — research only | Not licensed — research only |