Epithalon vs SS-31: Telomeres vs Mitochondria, Evidence, Cost, and Which One Fits

Epithalon is a tetrapeptide, Ala-Glu-Asp-Gly (AEDG). It was designed in the 1990s at the St Petersburg Institute of Bioregulation and Gerontology, led by Vladimir Khavinson, to reproduce the amino-acid composition of Epithalamin, a crude bovine pineal extract the same group had given to elderly patients for years. That lineage matters: much of the human data quoted online for epithalon was generated with the extract, not the synthetic peptide. It is not melatonin, not a sedative and not a hormone. The full reference is at what is Epithalon.

• Telomerase in cultured human cells. A 2003 paper in the Bulletin of Experimental Biology and Medicine reported that epithalon induced telomerase and lengthened telomeres in cultured human fetal fibroblasts. In 2025 a group at Brunel University London published in Biogerontology the first independent replication in normal human cell lines, and also reported telomere extension in breast cancer cell lines.
• Evening melatonin where it is low. A 2001 study in old female rhesus monkeys reported evening melatonin rising more than fourfold and evening cortisol falling; younger monkeys showed no change. A 2004 paper reported the parent extract raising night-time melatonin in elderly people whose pineal output was low.
• Antioxidant and anti-inflammatory activity in cells. 2022 papers in Aging and the International Journal of Molecular Sciences describe effects on oxidative damage in mouse oocytes and on inflammatory signalling in a human monocyte line.

There are no randomized, placebo-controlled trials of injectable epithalon in humans for any indication. What exists in people is the Khavinson elderly cohorts (with the Epithalamin extract, open-label, from the originating institute), a small Russian-language study of a sublingual spray in women working night shifts that measured a urinary melatonin metabolite rather than sleep, and an uncontrolled retinal case series. When the FDA reviewed epithalon in July 2026 it found no human pharmacokinetic data and no study of the subcutaneous route.

SS-31 is also a tetrapeptide, built in an alternating aromatic and cationic pattern that lets it cross cell membranes and concentrate on the inner mitochondrial membrane without depending on membrane potential. It was developed by Hazel Szeto and Peter Schiller; its development code was MTP-131 and its generic name is elamipretide. In September 2025 the FDA granted accelerated approval to a branded elamipretide product for one rare genetic disease, Barth syndrome. The compounded vial is not that product. The full reference is at what is SS-31.

• Binding cardiolipin. A 2013 paper in the Journal of the American Society of Nephrology reported high-affinity binding to cardiolipin, a lipid found almost only in the inner mitochondrial membrane, and protection of the cristae (the membrane folds where ATP is made) in rat kidneys after ischaemia.
• Stopping cytochrome c acting as a peroxidase. The same work reports the peptide and cardiolipin complex inhibiting a self-damaging peroxidase activity while leaving electron transport intact. That is the specific sense in which SS-31 is said to reduce reactive oxygen species.
• Faster ATP recovery. Animal work reports faster recovery of ATP once blood flow returns.

SS-31 has more human trial data than almost any other compounded peptide, and the results are mixed. Randomized, double-blind, placebo-controlled trials ran in four diseases at 40 mg daily: TAZPOWER in Barth syndrome, MMPOWER-3 in primary mitochondrial myopathy (218 people), PROGRESS-HF in heart failure and ReCLAIM-2 in dry macular degeneration. The randomized primary endpoints were missed in every one. The positive findings are open-label improvements in Barth syndrome sustained to 168 weeks, a fatigue signal in a short myopathy crossover, a genotype subgroup in the phase 3, and a secondary imaging endpoint in the eye trial. There are no randomized trials in healthy adults or for any longevity use.

Epithalon is the one discussed when the interest is the telomere and circadian side of ageing, or the Khavinson longevity programme as a whole. Prescribers note the melatonin findings appear where output was already low, so people with a regular day and night rhythm are the least likely to notice anything. It is a more cautious conversation for anyone with a personal or strong family history of cancer.

SS-31 is the one discussed when the interest is mitochondrial function and cellular energy. It suits someone who understands that the trial dose was 40 mg a day in people with diagnosed mitochondrial disease, that the compounded dose is a small fraction of that, and that no trial shows what the compounded dose does. Anyone with Barth syndrome or a diagnosed primary mitochondrial disease belongs with a specialist and the approved product, not a compounded vial.

They act on different systems, and some physicians prescribe them in the same period. No study has tested the combination, so it means two unknowns at once. Whether a combination is appropriate for you is something your physician weighs after reviewing your intake.