SS-31, also known as elamipretide, is a synthetic tetrapeptide designed to reach a specific subcellular destination: the inner mitochondrial membrane. It belongs to a family of Szeto-Schiller peptides characterised by an alternating motif of cationic and aromatic side chains.
How it reaches the mitochondrion
This is the unusual part. Despite carrying a strong positive charge, SS peptides cross the plasma membrane in a manner that is energy-independent and non-saturable — they do not rely on a transporter. Once inside, they accumulate at the inner mitochondrial membrane at concentrations reported to be 1,000 to 5,000-fold higher than in the surrounding cytosol.
Molecular target: cardiolipin
SS-31 binds cardiolipin, a phospholipid found almost exclusively in the inner mitochondrial membrane and essential to the organisation of the electron transport chain. The interaction is biophysical rather than receptor-mediated: SS-31 associates with the lipid bilayer and alters surface electrostatics.
The proposed consequence is stabilisation of cardiolipin-dependent membrane architecture, supporting electron transport chain organisation and reducing reactive oxygen species generated by inefficient electron flow.
How this differs from MOTS-c
Both are studied against mitochondrial endpoints, but they are not interchangeable. SS-31 is nuclear-encoded, synthetic, and acts structurally — at the biophysical level of membrane organisation. MOTS-c is mitochondrially encoded and acts as a signalling molecule through AMPK, modulating metabolism transcriptionally.
One protects architecture; the other changes signalling. Research designs that treat them as substitutes are measuring different things.
Research status
Elamipretide has been examined in registered clinical trials including work in Friedreich’s ataxia and primary mitochondrial myopathy. That gives it a more developed human record than most compounds in this catalogue, though it remains investigational and unapproved.
Supplied lyophilised. See our reconstitution protocol for handling technique and diluent selection.
Every batch ships with a third-party certificate of analysis. View SS-31 and its current COA.
Research use only
Isla Longevity supplies this compound for laboratory research use only. It is not approved by the FDA for human or veterinary use and is not for human consumption. This article summarises published research and is not medical guidance.
