--- title: "SS-31 | PepTracker Pro" url: https://peptrackerpro.com/peptides/ss-31 description: "A mitochondria-targeted peptide FDA-approved as FORZINITY (elamipretide) for Barth syndrome in September 2025 — the first FDA-approved mitochondrial-targeted therapeutic." lang: en --- Skip to main content **Educational information only.** This site does not provide medical advice. Read full disclaimer (https://peptrackerpro.com/disclaimer) **Research-only content.** This page is for educational purposes and does not constitute medical advice. Read full disclaimer → (https://peptrackerpro.com/research-disclaimer) # SS-31 High Evidence A mitochondria-targeted peptide FDA-approved as FORZINITY (elamipretide) for Barth syndrome in September 2025 — the first FDA-approved mitochondrial-targeted therapeutic. Aliases Elamipretide +2 more Evidence High Evidence Last Updated 2026-07-17 Reading Time 2 min ## What It Is SS-31, now marketed as FORZINITY (elamipretide HCl), is a mitochondria-targeted tetrapeptide (D-Arg-DMT-Lys-Phe-NH2) that selectively binds to cardiolipin in the inner mitochondrial membrane, stabilizing cristae structure, reducing oxidative stress, and enhancing ATP production. On September 19, 2025, it became the first FDA-approved mitochondria-targeted therapeutic, receiving accelerated approval for Barth syndrome — a rare, life-limiting genetic disorder affecting approximately 150 individuals in the United States. The approval was supported by the TAZPOWER clinical trial, which demonstrated improved knee extensor muscle strength in Barth syndrome patients. A comprehensive review published in the International Journal of Molecular Sciences (January 2026) detailed SS-31's broad therapeutic potential across cardiovascular, ophthalmic, renal, and neurodegenerative applications. Notably, SS-31 selectively improves aged mitochondria without affecting young healthy mitochondria — increasing ATP production, reducing H2O2 output, and reversing energetic deficits in aged mouse skeletal muscle. A 2024 study in Scientific Reports demonstrated that SS-31 treatment ameliorated cardiac mitochondrial morphology and defective mitophagy in a murine model of Barth syndrome. The Phase 2/3 clinical trial program and precise cardiolipin-binding mechanism make SS-31 arguably the most clinically validated peptide in the mitochondrial medicine space. Active clinical development continues for heart failure with preserved ejection fraction (HFpEF), primary mitochondrial myopathy, and age-related macular degeneration (dry AMD). In 2026, SS-31 is the only mitochondrial peptide with Phase III trial data, and older adults receiving SS-31 in clinical studies showed improved mitochondrial respiration and reduced oxidative stress — their muscle mitochondria moved measurably toward younger adult profiles. As of May 2026, SS-31 remains the most clinically validated compound in the emerging field of mitochondrial medicine, with growing research interest driven by longevity and anti-aging science communities. The most common adverse reactions are injection site reactions. Also known as: Elamipretide, Bendavia, MTP-131 ## Regulatory Status FDA-Approved (Accelerated) FORZINITY (elamipretide HCl) received FDA accelerated approval September 19, 2025 to improve muscle strength in adult and pediatric patients with Barth syndrome weighing ≥30 kg. First FDA-approved mitochondria-targeted therapeutic. Effective: September 2025 View FDA Source (https://www.fda.gov/) ## Evidence Snapshot High Evidence Low Medium High ## Commonly Discussed Benefits Longevity: https://peptrackerpro.com/benefits/longevity Anti-Aging: https://peptrackerpro.com/benefits/anti-aging Recovery: https://peptrackerpro.com/benefits/recovery Neuroprotection: https://peptrackerpro.com/benefits/neuroprotection Researching SS-31? Track it, set reminders, and keep notes in the free app. Track in App (https://app.peptrackerpro.com/?add=ss-31) ## Safety & Cautions - FDA-approved only for Barth syndrome; other indications remain investigational - Accelerated approval pathway — confirmatory trials may be required - Off-label use for anti-aging or longevity not supported by clinical evidence - Requires subcutaneous injection under medical supervision ## Comparisons See how SS-31 compares to related peptides: SS-31 vs Epithalon: https://peptrackerpro.com/compare/ss-31-vs-epithalon SS-31 vs Humanin: https://peptrackerpro.com/compare/ss-31-vs-humanin SS-31 vs Motixafortide (Aphexda): https://peptrackerpro.com/compare/ss-31-vs-motixafortide SS-31 vs MOTS-c: https://peptrackerpro.com/compare/ss-31-vs-mots-c SS-31 vs NAD+: https://peptrackerpro.com/compare/ss-31-vs-nad ## Calculator Tools Use our research tools to explore dosing and reconstitution data: Reconstitution Calculator: https://peptrackerpro.com/calculators ## Citations 1. [1] FDA Approves FORZINITY (elamipretide) for Barth Syndrome — Stealth BioTherapeutics, September 2025 PubMed (https://stealthbt.com/stealth-biotherapeutics-announces-fda-accelerated-approval-of-forzinity-elamipretide-hcl/) 2. [2] UMDF — FDA Approves First Mitochondrial Disease Therapy PubMed (https://umdf.org/fda-approves-elamipretide/) 3. [3] Johns Hopkins Hub — FDA approves drug for Barth syndrome, September 2025 PubMed (https://hub.jhu.edu/2025/09/25/fda-approves-barth-syndrome-treatment/) 4. [4] Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential — IJMS. 2026 PubMed (https://www.mdpi.com/1422-0067/26/3/944) 5. [5] SS-31 treatment ameliorates cardiac mitochondrial morphology in Barth syndrome model — Scientific Reports. 2024 PubMed (https://www.nature.com/articles/s41598-024-64368-y) ### Keep researching in the app - Log SS-31 to your private tracker - Set a dosing reminder - Compare it side-by-side with your stack Open PepTracker Pro Free: https://app.peptrackerpro.com/?add=ss-31 Browse more peptides: https://peptrackerpro.com/peptides ## Related Peptides ### Epithalon Low Evidence A tetrapeptide studied for its potential to activate telomerase and influence biological aging markers. Longevity: https://peptrackerpro.com/benefits/longevity Anti-Aging: https://peptrackerpro.com/benefits/anti-aging Sleep: https://peptrackerpro.com/benefits/sleep Immune Support: https://peptrackerpro.com/benefits/immune-support View Details: https://peptrackerpro.com/peptides/epithalon \+ Compare: https://peptrackerpro.com/compare?select=epithalon Track in App: https://app.peptrackerpro.com/?add=epithalon ### Humanin Low Evidence An endogenous mitochondrial-derived peptide studied for neuroprotection, cellular stress resistance, and longevity, whose blood levels fall with age and are elevated in centenarians. Longevity (https://peptrackerpro.com/benefits/longevity)Anti-Aging (https://peptrackerpro.com/benefits/anti-aging)Neuroprotection (https://peptrackerpro.com/benefits/neuroprotection)Metabolism (https://peptrackerpro.com/benefits/metabolism)+1 more View Details: https://peptrackerpro.com/peptides/humanin \+ Compare: https://peptrackerpro.com/compare?select=humanin Track in App: https://app.peptrackerpro.com/?add=humanin ### Motixafortide (Aphexda) High Evidence An FDA-approved synthetic cyclic peptide and CXCR4 antagonist (brand name Aphexda; research name BL-8040) used together with G-CSF to mobilize blood-forming stem cells for autologous transplant in multiple myeloma. In 2026 it is being actively studied as part of combination immunotherapy for pancreatic cancer. Hematology: https://peptrackerpro.com/benefits/hematology Oncology: https://peptrackerpro.com/benefits/oncology Immune Modulation: https://peptrackerpro.com/benefits/immune-modulation View Details: https://peptrackerpro.com/peptides/motixafortide \+ Compare: https://peptrackerpro.com/compare?select=motixafortide Track in App: https://app.peptrackerpro.com/?add=motixafortide ### MOTS-c Low Evidence A mitochondrial-derived peptide studied for metabolic regulation, exercise mimetic effects, and longevity. Metabolism (https://peptrackerpro.com/benefits/metabolism)Fat Loss (https://peptrackerpro.com/benefits/fat-loss)Longevity (https://peptrackerpro.com/benefits/longevity)Muscle Growth (https://peptrackerpro.com/benefits/muscle-growth)+2 more View Details: https://peptrackerpro.com/peptides/mots-c \+ Compare: https://peptrackerpro.com/compare?select=mots-c Track in App: https://app.peptrackerpro.com/?add=mots-c ### NAD+ Medium Evidence A coenzyme essential for cellular energy production, studied for anti-aging and metabolic support. Energy (https://peptrackerpro.com/benefits/energy)Longevity (https://peptrackerpro.com/benefits/longevity)Anti-Aging (https://peptrackerpro.com/benefits/anti-aging)Metabolism (https://peptrackerpro.com/benefits/metabolism)+1 more View Details: https://peptrackerpro.com/peptides/nad \+ Compare: https://peptrackerpro.com/compare?select=nad Track in App: https://app.peptrackerpro.com/?add=nad ## Structured data ```json [ { "@context": "https://schema.org", "@type": "Organization", "name": "PepTracker Pro", "url": "https://peptrackerpro.com", "logo": "https://peptrackerpro.com/favicon.png", "description": "Evidence-based educational resource dedicated to improving peptide research literacy.", "contactPoint": { "@type": "ContactPoint", "email": "hello@peptrackerpro.com", "contactType": "customer support" }, "sameAs": [] }, { "@context": "https://schema.org", "@type": "MedicalWebPage", "name": "SS-31", "description": "A mitochondria-targeted peptide FDA-approved as FORZINITY (elamipretide) for Barth syndrome in September 2025 — the first FDA-approved mitochondrial-targeted therapeutic.", "url": "https://peptrackerpro.com/peptides/ss-31", "lastReviewed": "2026-07-17", "reviewedBy": { "@type": "Organization", "name": "PepTracker Pro Research Team", "url": "https://peptrackerpro.com" }, "isPartOf": { "@type": "WebSite", "name": "PepTracker Pro", "url": "https://peptrackerpro.com" } }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://peptrackerpro.com" }, { "@type": "ListItem", "position": 2, "name": "Peptides", "item": "https://peptrackerpro.com/peptides" }, { "@type": "ListItem", "position": 3, "name": "SS-31", "item": "https://peptrackerpro.com/peptides/ss-31" } ] }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "People researching mitochondrial-targeted therapies?", "acceptedAnswer": { "@type": "Answer", "text": "SS-31 is a research peptide studied in preclinical models. 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