Designed to reach one membrane
SS-31 is a short peptide with an alternating charge pattern that lets it accumulate at the inner mitochondrial membrane. Unlike compounds that act on a receptor at the cell surface, the design question here was one of delivery: getting the molecule to a specific place inside the cell.
Its proposed target is cardiolipin, a lipid found almost exclusively in that membrane and closely involved in how the respiratory chain is organised. Cardiolipin changes with age and in various disease states, which is what makes it a target of interest.
Anyone searching what is SS-31 will quickly find two names for one molecule, and reading around both is the fastest route to the properly designed human trials rather than the forum summaries that tend to surface first.
Elamipretide, and what that means
Under the name elamipretide the compound has been through clinical programmes for several mitochondrial conditions. That means there are properly designed human studies to read, including ones that did not produce the hoped-for result.
Trials that miss their endpoint are more informative than most published literature, because they tell you where a mechanism did not translate. Anyone citing only the positive findings is giving you half the picture.
Both outcomes belong to the same file and both are public. The registry entries on ClinicalTrials.gov set out what each study was designed to measure, and the results indexed on PubMed show what was reported once it had run. Reading them in that order, design first, findings second, is the habit that keeps a mixed record from being summarised as a clean one.
| Length | 4 amino acids |
| Also called | Elamipretide |
| Proposed target | Cardiolipin, inner mitochondrial membrane |
| Design principle | Charge pattern drives accumulation |
| Format | Pre-filled peptide pen |
| Purity | ≥ 99% (HPLC) |
| Evidence base | Includes clinical trials, with mixed results |
| Category | Research use only |
Identity, format and purity. Nothing beyond that is being asserted.
Why it sits in the longevity group
Mitochondrial function declines in characteristic ways with age, which is why compounds targeting that organelle appear in both energy and ageing research. SS-31 is studied from both directions.
That said, a compound in clinical development for a specific mitochondrial condition is not the same as a compound demonstrated to affect ageing, and the two get conflated regularly.
The merging happens in a predictable direction. A result obtained in a defined patient group gets restated as a general property of the molecule, because the general version is the more interesting sentence. Neighbours in this part of the catalogue attract the same treatment: on the epitalon page it is a cell-culture reading that quietly becomes a claim about whole organisms.
Reaching a lipid inside the mitochondrion
Most compounds in this catalogue are described by what they bind. This one is more usefully described by where it ends up, and that difference changes which experiments count as evidence: showing that a molecule concentrates in the right compartment is a separate demonstration from showing that anything follows once it is there.
A short peptide still has to survive storage before any of that matters. Kept dry, cold and dark it is stable enough; in solution the usual limits apply, which the storage and shelf-life page sets out for any sequence you reconstitute. It is supplied, like the rest of the catalogue, for research use only.
SS-31 in the catalogue
A 99% HPLC minimum applies to everything we put on the shelf, certificate included.
Where SS-31 fits in
What to read next, in the order that makes most sense.
About SS-31
Common queries, without the hedging.