This SS-31 (Elamipretide) Research Guide is part of the Pyrox Labs Knowledge Hub — for laboratory and research use only. Not for human or veterinary use.
WHAT IS SS-31?
SS-31 (development code MTP-131, also known as elamipretide or by the brand name Bendavia in some trial contexts) is a synthetic, mitochondria-targeted tetrapeptide — a member of the “Szeto-Schiller” peptide family designed to concentrate selectively at the inner mitochondrial membrane. Of the compounds in this Knowledge Hub, SS-31 has the most extensive human clinical trial history, spanning several disease areas with genuinely mixed results. This guide summarises the published literature — positive and negative — on SS-31 for laboratory researchers.
RESEARCH BACKGROUND
Published literature — see this PubMed literature search — has explored areas including:
- Primary mitochondrial myopathy: the Phase 3 MMPOWER-3 trial (n=218) did not meet its primary endpoints (6-minute walk test, fatigue score) versus placebo, though a post-hoc subgroup with nuclear DNA pathogenic variants showed a positive signal, reported as hypothesis-generating rather than confirmatory
- Barth syndrome: the TAZPOWER trial (randomised, double-blind crossover, n=12) did not meet its primary endpoints
- Heart failure: results have varied by trial — a 28-day Phase 2 study (n=71) found no significant improvement in cardiac volume/function measures, while the smaller PROGRESS trial (n=36) reported significant improvement in left ventricular measures and 6-minute walk distance in heart failure with preserved ejection fraction (HFpEF)
- Dry age-related macular degeneration: Phase 1 and Phase 2 (ReCLAIM, ReCLAIM-2) trials have studied elamipretide’s safety profile and effects on visual function and geographic atrophy progression
PROPOSED MECHANISM OF ACTION
SS-31 is studied for its selective, reversible binding to cardiolipin — an anionic phospholipid found almost exclusively in the inner mitochondrial membrane — via electrostatic interaction. This is proposed to stabilise cristae structure, support electron transport chain assembly and ATP synthase function, and reduce reactive oxygen species (ROS) generation. Despite carrying a strong positive charge, SS-31 crosses the plasma membrane through an energy-independent mechanism and is reported to concentrate 1,000–5,000-fold at the inner mitochondrial membrane relative to other cellular compartments — an unusually well-characterised targeting mechanism for a peptide of this size.
SS-31 RESEARCH GUIDE — HANDLING & STORAGE
- Store lyophilised SS-31 vials in a freezer (-20°C), protected from light, for long-term storage.
- Once reconstituted, store refrigerated (2–8°C) and use within the timeframe indicated by your research protocol. Higher-concentration solutions have been noted to carry increased peptide aggregation risk.
- Use sterile technique and appropriate PPE when handling.
- See our Reconstitution Guide for general laboratory reconstitution reference information.
CERTIFICATES OF ANALYSIS
Independently tested for purity and identity. Search by product name and the batch/lot number printed on your vial label.
FREQUENTLY ASKED QUESTIONS
Is SS-31 approved for human use?
The SS-31/elamipretide sold by Pyrox Labs is not approved for human or veterinary use. Its broader clinical development programme has produced a mix of positive and negative trial results across different indications — see the Research Background section above.
Can Pyrox Labs advise on dosing or administration?
No. We do not provide dosing, administration, or treatment guidance of any kind. Our team can only answer questions relating to order status, product specifications, and COA/testing documentation.
Did SS-31’s clinical trials succeed or fail?
Both — genuinely. Several major trials (MMPOWER-3, TAZPOWER, and one heart failure study) did not meet their primary endpoints, while others (PROGRESS, subgroup analyses, AMD safety trials) reported positive results. Researchers should treat SS-31 as an evolving, not uniformly positive, evidence base.
How is SS-31 supplied for laboratory research?
Pyrox Labs supplies SS-31 as a lyophilised (freeze-dried) powder in a sealed research vial, accompanied by a Certificate of Analysis confirming purity and identity.
Research Use Disclaimer: SS-31 products sold by Pyrox Labs are intended solely for in-vitro laboratory research and are not for human consumption, veterinary use, or any form of personal use. By purchasing, you confirm you are a qualified researcher or institution and agree to our full Research Use Disclaimer and Terms & Conditions.
Related: MOTS-C Research Guide · NAD+ Research Guide · Reconstitution Guide · COA Hub
