What Is SS-31? Elamipretide Explained
SS-31, also called elamipretide, is a four-amino-acid peptide designed to reach the inner membrane of mitochondria. In 2025 it became the first FDA-approved treatment for Barth syndrome. Here is how it works.
SS-31 at a glance
SS-31 is a synthetic tetrapeptide (four amino acids) also known by its drug name elamipretide. It belongs to the Szeto-Schiller (SS) peptides, named after Hazel Szeto and Peter Schiller, who designed them. Unlike most peptides, it crosses cell membranes and concentrates in the inner membrane of mitochondria. It is also written SS31.
- Drug name
- Elamipretide
- Sequence
- D-Arg-Dmt-Lys-Phe-NH2
- Length
- 4 amino acids
- Target
- Cardiolipin
- Our vial
- 10mg
How it works
The inner mitochondrial membrane contains a fat called cardiolipin, which holds the energy-producing protein complexes in place. SS-31 binds cardiolipin. Research suggests this helps keep those complexes organised and reduces the leakage of reactive oxygen species. Its unusual building blocks, D-arginine and dimethyltyrosine (Dmt), give it the alternating charge pattern that lets it pass through membranes.
- MOTS-c16
- SS-314
- Glutathione3
From research to approval
- 2000sSzeto-Schiller peptides are developed and shown to target mitochondria.
- 2010sStealth BioTherapeutics runs clinical trials as elamipretide.
- 2019A phase 3 trial in primary mitochondrial myopathy misses its main goal.
- May 2025FDA issues a complete response letter for Barth syndrome.
- Sept 2025FDA grants accelerated approval (Forzinity) for Barth syndrome, a rare mitochondrial disease.
It is not approved in Australia. Research-grade SS-31 is supplied for laboratory use.
SS-31 vs MOTS-c
SS-31 is a synthetic peptide designed to reach mitochondria; MOTS-c is a natural peptide made by mitochondria. Both feature in our cellular research comparison. We stock SS-31 in 10mg vials.
Further reading
For laboratory research use only. Not for human consumption. Not medical or legal advice.
