SS-31

A short synthetic peptide that concentrates in the inner mitochondrial membrane, studied as a drug for mitochondrial disease rather than as a wellness compound.

What it is

SS-31 is a four amino acid peptide, developed as elamipretide, that carries a positive charge and accumulates several thousandfold in the inner mitochondrial membrane. There it binds cardiolipin, a phospholipid found almost nowhere else in the cell, which is what gives the peptide its unusual targeting.

Cardiolipin holds the proteins of the electron transport chain in the right arrangement. When it is oxidized or mislocalized, the chain leaks electrons and the cell produces energy less efficiently. In laboratory models, binding cardiolipin protects that architecture, which is the basis for every claim made about the peptide.

What the human evidence shows

This is a pharmaceutical compound rather than a supplement, and it has been through real trials. In primary mitochondrial myopathy, the MMPOWER-2 crossover study reported an improvement in six minute walk distance at the highest dose, but the larger MMPOWER-3 trial did not meet its primary endpoints after 24 weeks.

It has also been studied in Barth syndrome and in dry age-related macular degeneration. Nothing in that record supports use by healthy adults for energy, recovery or aging. The peptide is not approved for any longevity or wellness use, and its only US approval is an accelerated approval for Barth syndrome granted in 2025.

Why people bring it up

SS-31 appears in longevity conversations because mitochondrial decline is a real feature of aging and because the mechanism is genuinely elegant. The gap is between mechanism and outcome. A compound can do exactly what the biochemistry says and still fail to change how a person feels or functions, which is what the phase 3 result suggests here.

Material sold online as SS-31 is research chemical supply, not pharmaceutical product, with no assurance of identity, purity or sterility.

Baseline does not dispense this. It is here because people ask about it, and because an honest read of the evidence is more useful than a sales page.

References

  1. Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. Br J Pharmacol. 2014.
  2. Karaa A, et al. Randomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy (MMPOWER-2). Neurology. 2018.
  3. Karaa A, et al. A randomized trial of elamipretide in patients with primary mitochondrial myopathy (MMPOWER-3). Neurology. 2023.