Last updated 18 September 2026 · SARMs Store editorial team. Products on this site are supplied strictly for laboratory research and are not for human consumption. This guide summarises published research; it is not medical advice and contains no instructions for use. 18+ only.
SS-31 at a glance
| Class | Aromatic-cationic tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) that binds cardiolipin in the inner mitochondrial membrane |
|---|---|
| Developed by | Hazel Szeto and Peter Schiller (the SS in the name), Cornell, 2000s; Stealth BioTherapeutics |
| Highest evidence | Phase II and III human trials; US FDA accelerated approval for Barth syndrome in 2025 as Forzinity |
| Studied for | Mitochondrial function in heart failure, mitochondrial myopathy, Barth syndrome, dry age-related macular degeneration |
| Format | Lyophilised vial (10mg) |
| Storage | 2 to 8°C unopened, away from light |
| UK status 2026 | Research chemical; not a UK-licensed medicine; not named on the WADA list |
What SS-31 is
SS-31, generic name elamipretide, is a four-amino-acid peptide designed by Hazel Szeto and Peter Schiller to concentrate in mitochondria. It binds cardiolipin, a lipid unique to the inner mitochondrial membrane, and in cell and animal studies stabilises the electron transport chain, improving ATP production and reducing the leak of reactive oxygen species. It is one of the few research peptides that has been through full clinical development.
What the research found
Barth syndrome. Barth syndrome is a rare inherited cardiolipin disorder. The TAZPOWER trial and its open-label extension reported improvements in muscle strength and cardiac measures over long-term treatment, and in 2025 the US FDA granted elamipretide accelerated approval for Barth syndrome under the brand Forzinity. This is the first regulatory approval of a mitochondria-targeted peptide.
Primary mitochondrial myopathy. The phase III MMPOWER-3 trial (2019) did not meet its primary endpoints on walking distance and fatigue, and development for that indication stopped.
Heart failure. Phase II studies in heart failure with reduced ejection fraction showed changes in cardiac volumes in some analyses but no programme has gone to phase III.
Dry AMD. The ReCLAIM-2 trial in geographic atrophy reported mixed results in 2022; a further programme is ongoing.
Animal studies. A large body of rodent work reports protection of heart, kidney and skeletal muscle mitochondria in injury and ageing models, including improved exercise performance in old mice, which is the source of most research-market interest.
What is missing. Any trial in healthy adults for performance or ageing.
Stability, storage and handling
Supplied lyophilised in a sealed vial. Keep unopened vials at 2 to 8 degrees Celsius or frozen for long storage, away from light. Reconstituted solutions degrade over days to weeks. The certificate should show HPLC purity and mass spectrometry identity.
Legal status in the UK, 2026
Not a controlled substance under the Misuse of Drugs Act 1971. Elamipretide holds no UK or EU marketing authorisation; the 2025 approval is US only, for one rare disease, as a specific licensed product. Research-grade SS-31 is not that product and cannot be sold or advertised for human use in the UK; supplied strictly for laboratory research. Not named on the WADA Prohibited List.
What to check before buying
Milligrams per vial, HPLC purity, mass spectrometry identity, a batch number matching the certificate, and cold-chain shipping. Every Origin Peptides batch is independently tested and its certificate of analysis is published on the product page and the Lab Testing page.
Frequently asked questions
Is SS-31 the same as elamipretide?
Yes. SS-31 is the research code, elamipretide the generic name, Forzinity the US brand.
Is SS-31 an approved medicine?
In the United States, for Barth syndrome only, since 2025. Not in the UK or EU. The research vial is not the licensed product.
What does it do to mitochondria?
It binds cardiolipin in the inner membrane and, in cell and animal studies, stabilises the electron transport chain.
Is SS-31 legal in the UK?
Legal to buy and possess as a research compound; not lawful to sell or advertise for human consumption.
Key references
Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. British Journal of Pharmacology. 2014;171(8):2029-2050. Reid Thompson W, Hornby B, Manuel R, et al. A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome. Genetics in Medicine. 2021;23(3):471-478. Karaa A, Bertini E, Carelli V, et al. Efficacy and safety of elamipretide in individuals with primary mitochondrial myopathy: the MMPOWER-3 randomized clinical trial. Neurology. 2023;101(3):e238-e252.
Related guides
- NAD+ research guide
- Epithalon research guide
- SARMs vs peptides: what the research compares
- How to read a certificate of analysis
- SARMs 101 hub
Research products: Origin Peptides SS-31 10mg · NAD+ 500mg · Full Origin Peptides range · Lab Testing