SS-31 (Elamipretide): A Peptide That Targets the Mitochondrial Membrane

SS-31 — also called elamipretide — is a four-amino-acid peptide that accumulates in the inner mitochondrial membrane and binds cardiolipin. That is a specific molecular target, which is rarer in this category than the marketing suggests.

It has also been through genuine clinical development under the name elamipretide, which means there is trial evidence rather than only preclinical work.

What cardiolipin has to do with it

Cardiolipin is a phospholipid found almost exclusively in the inner mitochondrial membrane, where it helps organise the protein complexes of the electron transport chain. When cardiolipin is disrupted, those complexes work less efficiently.

SS-31 binds cardiolipin and is described as stabilising that organisation — improving electron transport efficiency and reducing reactive oxygen species production. The peptide is designed to concentrate in mitochondria, which is why it reaches a target most compounds cannot.

How it differs from MOTS-c

Both are described as mitochondrial peptides, and they are not doing the same thing.

The MOTS-c guide covers the other side. SS-31 is a designed molecule aimed at a structure; MOTS-c is a natural signalling peptide.

What the trials found

Elamipretide has been studied in primary mitochondrial myopathy, Barth syndrome, heart failure, and dry age-related macular degeneration — serious conditions with a mitochondrial component.

The record is genuinely mixed, and both halves are informative:

• Encouraging signals in some rare mitochondrial disease work, where the mechanism is most directly relevant.

• Missed primary endpoints in other programmes, including trials that did not meet their pre-specified outcome.

The vial math

SS-31 is supplied lyophilised, commonly in 50 mg vials, with figures discussed in the low milligram range.

A 50 mg vial is large relative to the amounts discussed, which raises the same problem as GHK-Cu and the blends: a lot of solution to use inside the 28-day window. The peptide calculator handles the conversion.

Storage

Storage is the same as any reconstituted vial: 2–8 °C, protected from light, never frozen, and bounded by the shorter of peptide stability and the 28-day limit on bacteriostatic water. The bacteriostatic water guide covers the detail.

Frequently asked questions

Is SS-31 the same as elamipretide?

Yes. SS-31 is the research designation; elamipretide is the name used in clinical development.

Is it approved?

No. It has been through trials without securing approval in the US, EU, or UK.

Does it work as an anti-ageing compound?

The trials were in specific mitochondrial and cardiac conditions, not in healthy ageing. Extending the mechanism to general anti-ageing use is an inference the evidence does not make.