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SS-31: quick citable summary
SS-31 is listed by PeptaHub as a longevity peptide with a prescription legal-status classification. The page summarizes mechanism, research context, common routes, safety notes, and references for writers and AI answer engines.
PeptaHub. “SS-31: Mechanism, Research Context, Safety.” peptahub.com, 2026. https://peptahub.com/peptides/ss-31. Licensed CC BY 4.0.
License: Creative Commons Attribution 4.0 International. Link back to https://peptahub.com/peptides/ss-31.
What is SS-31?
SS-31 (elamipretide) is a mitochondria-targeted tetrapeptide that binds cardiolipin on the inner mitochondrial membrane, optimizing electron transport and reducing oxidative stress. It holds FDA accelerated approval as Forzinity for improving muscle strength in Barth syndrome.
Overview
SS-31 (Elamipretide) is a mitochondria-targeted tetrapeptide that concentrates in the inner mitochondrial membrane. Developed by Hazel Szeto at Weill Cornell Medical College, it received FDA accelerated approval in September 2025 as Forzinity for improving muscle strength in Barth syndrome, and has been studied in trials for heart failure and age-related macular degeneration. It is the most clinically advanced of the mitochondria-targeted peptides.
Mechanism of action
SS-31 selectively binds to cardiolipin, a phospholipid unique to the inner mitochondrial membrane that is essential for electron transport chain (ETC) function. By stabilizing cardiolipin interactions with cytochrome c, SS-31 optimizes electron transfer, reduces electron leak and reactive oxygen species (ROS) production, and improves ATP synthesis. It concentrates 1000-5000x in mitochondria relative to cytoplasm due to its alternating aromatic-cationic structure.
Reported study ranges
| Purpose | Route | Reported range | Frequency | Notes |
|---|---|---|---|---|
| mitochondrial optimization | subcutaneous | 20–40 mg | daily | Clinical trial doses range from 4mg to 40mg daily. Limited availability outside clinical settings. 4-8 week cycles in research contexts. |
Reported ranges are for research context only. Consult a qualified healthcare professional before using any peptide.
Convert SS-31 research-range units
Need to convert mg to mcg, dose volume, or U-100 syringe units? The SS-31 dose calculator is preloaded with these ranges, or use the general dose unit converter.
Research summary
Elamipretide has been evaluated in Barth syndrome (TAZPOWER), heart failure (PROGRESS-HF) and dry age-related macular degeneration (ReCLAIM). TAZPOWER was a small randomized, double-blind, placebo-controlled crossover trial in 12 patients; the FDA granted accelerated approval on the strength of the muscle-strength data, and continued approval is contingent on confirmatory trials. Improvement in cardiac function has not been established as an approved effect. Animal studies report improved mitochondrial function, cardiac protection, kidney protection and skeletal muscle recovery, but those are preclinical results and have not been reproduced as clinical endpoints in humans.[1][2][3][4]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with SS-31 for synergistic effects.
Legal status
FDA granted accelerated approval to elamipretide HCl (Forzinity, Stealth BioTherapeutics) on September 19, 2025, to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. The approved regimen is 40 mg subcutaneously once daily. This is a narrow orphan indication — no approval exists for heart failure, macular degeneration, anti-aging or general mitochondrial support. Continued approval may depend on verification of clinical benefit in confirmatory trials.
Sourcing & access
Prescription required
SS-31 is an FDA-approved prescription medication available through licensed healthcare providers, pharmacies, and label-appropriate access programs; compounded access depends on current FDA shortage status and compounding rules.
Frequently asked questions
SS-31, also known as elamipretide or Bendavia, is a mitochondria-targeted tetrapeptide developed by Hazel Szeto at Weill Cornell Medical College. It concentrates in mitochondria relative to cytoplasm and is the most clinically advanced of the mitochondria-targeted peptides, holding an FDA accelerated approval for Barth syndrome.
SS-31 selectively binds cardiolipin, a phospholipid unique to the inner mitochondrial membrane essential for electron transport chain function. By stabilizing cardiolipin-cytochrome c interactions, it optimizes electron transfer, reduces reactive oxygen species, and improves ATP synthesis.
In clinical trials, reported side effects include injection site reactions, headache, dizziness, and nausea. Elamipretide is FDA-approved only as Forzinity for Barth syndrome, and that approval was an accelerated one based on a 12-patient trial, so the safety database in humans remains small. Any other use is off-label and unstudied.
SS-31 has been evaluated in the TAZPOWER crossover trial for Barth syndrome (n=12, the basis of its FDA accelerated approval), the PROGRESS-HF trial in heart failure, and the ReCLAIM trials in dry age-related macular degeneration. Animal studies report improvements in age-related mitochondrial dysfunction, but those findings are preclinical.
Research references
- First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergeticsReview
- The mitochondria-targeted peptide SS-31 binds lipid bilayers and modulates surface electrostatics as a key component of its mechanism of actionPubMed
- Mitochondrial protein interaction landscape of SS-31PubMed
- Peptide Szeto-Schiller 31 ameliorates doxorubicin-induced cardiotoxicity by inhibiting the activation of the p38 MAPK signaling pathwayPubMed