Summary

Elamipretide (SS-31, Bendavia™, MTP-131) is a mitochondria-targeted synthetic tetrapeptide developed by Stealth BioTherapeutics that selectively binds cardiolipin in the inner mitochondrial membrane, stabilising respiratory chain function and reducing oxidative stress. It has been evaluated in Phase 2 and Phase 3 clinical trials for primary mitochondrial myopathy (MMPOWER-3), Barth syndrome (TAZPOWER), and heart failure. Results show encouraging signals, particularly in Barth syndrome, though outcomes have been mixed across endpoints. Elamipretide is not a licensed medicine in the UK; it remains investigational for research purposes.

Mechanism

Elamipretide is a synthetic cell-permeable tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) that selectively accumulates in the inner mitochondrial membrane by binding with high affinity to cardiolipin — a phospholipid unique to mitochondria. Cardiolipin is essential for the structural integrity and function of mitochondrial respiratory chain complexes and supercomplexes. By stabilising cardiolipin, elamipretide helps maintain mitochondrial cristae structure, improves electron transport chain efficiency, reduces reactive oxygen species (ROS) production, and inhibits cytochrome c release — thereby protecting against mitochondria-mediated apoptosis. This mechanism is particularly relevant in conditions of mitochondrial dysfunction, oxidative stress, and apoptosis-driven tissue damage.

Protocols

In clinical trials, elamipretide has been administered via:

  • Subcutaneous injection: Once or twice daily (primary route in chronic disease trials)
  • Intravenous infusion: Used in perioperative cardiac surgery studies
  • Doses studied: Approximately 0.1–4 mg/kg/day, depending on trial and indication
  • Duration: 24 weeks in MMPOWER-3 (Phase 3), with open-label extensions to 48+ weeks
  • Most common adverse event: Injection-site reactions

This describes clinical trial methodology, not dosing recommendations. Elamipretide is not approved for use outside of clinical trials.

Elamipretide is not a licensed medicine in the UK and has not been approved by the MHRA for any indication. It is an investigational compound in clinical development by Stealth BioTherapeutics.

  • Not a controlled substance under the Misuse of Drugs Act 1971.
  • Not available on NHS prescription.
  • Research-grade material may be available from chemical supply companies for legitimate laboratory research; not licensed for human therapeutic use.
  • Purchasing for personal therapeutic use outside of a clinical trial is not permitted under UK law.

See our UK Legality Guide for further detail.

Vendor notes

Elamipretide is an investigational compound not approved anywhere in the world. We do not currently list any verified UK vendors. Researchers should source from established chemical supply companies with appropriate COAs and third-party purity testing.

References

  1. Karaa A, Haas R, Goldstein A, et al. A randomized, placebo-controlled trial of elamipretide in primary mitochondrial myopathy (MMPOWER-3). ClinicalTrials.gov NCT02805790. Available at: https://clinicaltrials.gov/study/NCT02805790.
  2. Thompson, et al. A phase 2/3 randomized, double-blind, placebo-controlled trial of elamipretide in Barth syndrome (TAZPOWER). 2021.
  3. Sabbah HN, et al. Chronic Therapy with Elamipretide (MTP-131), a Mitochondria-Targeted Peptide, Improves Left Ventricular Function and Remodeling in Dogs with Advanced Heart Failure. Circulation: Heart Failure. 2016;9(5):e002206. DOI: 10.1161/CIRCHEARTFAILURE.115.002206.
  4. Shi J, et al. Elamipretide (SS-31), a Mitochondria-Targeted Peptide, Improves Mitochondrial Dysfunction and Oxidative Stress in the Heart. Antioxidants. 2023.
  5. ClinicalTrials.gov. Search results for elamipretide. Available at: https://clinicaltrials.gov/search?term=elamipretide.