What Is SS-31 (Elamipretide)?
SS-31, also known by its development name Elamipretide and research designation MTP-131, is a synthetic tetrapeptide developed by Stealth BioTherapeutics that selectively targets the inner mitochondrial membrane. Unlike most research peptides that act on cell surface receptors, SS-31 concentrates at cardiolipin — a phospholipid unique to the inner mitochondrial membrane — making it a structurally and mechanistically distinct compound in the peptide research landscape.
SS-31 has been studied in the context of mitochondrial dysfunction across multiple disease models, including heart failure, ischemia-reperfusion injury, renal disease, and age-related muscle loss. It has advanced into Phase 2 and Phase 3 human trials, establishing one of the more robust clinical research profiles among mitochondria-targeting peptides.
SS-31 Mechanism of Action
SS-31’s mechanism is centered on its affinity for cardiolipin in the inner mitochondrial membrane:
- Cardiolipin stabilization: Binds to and stabilizes cardiolipin, which is critical for cristae structure and electron transport chain efficiency
- ROS scavenging: Reduces mitochondrial reactive oxygen species production, limiting oxidative damage to the inner membrane
- ATP synthesis improvement: By preserving cristae structure and cytochrome c association, SS-31 supports electron transport chain function and ATP production efficiency
- Cytochrome c retention: Reduces cytochrome c release from mitochondria, a key trigger for apoptotic signaling in ischemic models
SS-31 Research Data
SS-31 has been studied across multiple indications with human trial data available:
- Heart failure: The PROGRESS-HF trial studied SS-31 (elamipretide) in patients with heart failure with reduced ejection fraction. Treated patients showed improved left ventricular end-systolic volume index (LVESVI) compared to placebo, with favorable changes in quality of life measures
- Primary mitochondrial myopathy: A Phase 2 trial demonstrated improvements in distance walked in 6-minute walk tests and patient-reported fatigue scores in treated subjects
- Renal ischemia: Preclinical models have consistently shown SS-31 reduces markers of acute kidney injury following ischemia-reperfusion events
- Sarcopenia models: Animal aging studies have shown SS-31 preserves mitochondrial function in skeletal muscle, with associated improvements in grip strength and exercise capacity
SS-31 Dosage Reference
| Research Context | Dose Used in Studies | Route |
|---|---|---|
| Heart failure trials (human) | 0.05–0.25 mg/kg/day | IV infusion |
| Mitochondrial myopathy (human) | 40mg/day | Subcutaneous |
| Rodent ischemia models | 3–10 mg/kg | IV or IP |
| Aging/sarcopenia rodent models | 3 mg/kg/day | Subcutaneous |
Data from published peer-reviewed studies. Provided for research reference only — not dosing guidance for human use.
Side Effects from Trial Data
SS-31 has demonstrated a favorable tolerability profile across published trials:
- Injection site reactions (most common in subcutaneous administration studies)
- Mild and transient nausea in some IV administration cohorts
- No significant cardiac, hepatic, or renal toxicity signals in completed trials
- Generally well-tolerated across Phase 2 and Phase 3 study populations
SS-31 vs. MitoQ — Mitochondria-Targeting Compounds Comparison
| Parameter | SS-31 (Elamipretide) | MitoQ |
|---|---|---|
| Type | Tetrapeptide | Small molecule antioxidant |
| Target | Cardiolipin (inner membrane) | Mitochondrial matrix (ubiquinone) |
| Primary mechanism | Cristae stabilization, ROS reduction | Antioxidant electron carrier |
| Human trial data | Phase 2/3 completed | Limited |
| Route | Subcutaneous / IV | Oral |
Where to Buy SS-31 Peptide for Research
Given SS-31’s advanced clinical profile, researchers require high-purity material with documented identity verification. Key supplier criteria:
- HPLC purity ≥99% with documentation
- MS/MS identity confirmation to verify tetrapeptide sequence
- Third-party independent laboratory testing with COA
- Lyophilized format for storage stability
Core Power Peptides supplies SS-31 (Elamipretide) 10mg and 50mg vials at ≥99% purity, HPLC and MS/MS verified, with third-party COA available on request.
Research Disclaimer: All information on this page is for educational and scientific reference purposes only. SS-31/Elamipretide is not approved for general human use. This product is sold strictly for in vitro research and laboratory use only. Not for human consumption. Not medical advice.