# SS-31 > Source: https://chooseunscripted.com/peptide/ss-31/ > Content type: Peptide research profile > Last updated: September 4, 2026 **For research use only. Not for human or veterinary use.** ## Multi-Compound Blend No ## Product URL ## Scientific / Common Name SS-31 ## Alternative Names / Synonyms Elamipretide; SS-31; MTP-131; Bendavia; Forzinity; Elamipretide hydrochloride ## Molecular Formula C₃₂H₄₉N₉O₅ ## Molecular Weight 639.8 g/mol ## CAS Number 736992-21-5 ## Clinical Development Phase Approved ## Regulatory Status FDA accelerated approval ## Peptide Classification Mitochondria-Targeted Tetrapeptide / Szeto-Schiller Peptide ## Primary Research Focus Mitochondrial function; cardiolipin binding; inner mitochondrial membrane stabilization; electron transport chain support; oxidative stress modulation; ATP production; cellular bioenergetics; skeletal muscle function; mitochondrial disease research ## Mechanism Summary SS-31 is a **mitochondria-targeted tetrapeptide** that preferentially localizes to the **inner mitochondrial membrane** and interacts with **cardiolipin**, a phospholipid that plays a central role in mitochondrial membrane structure and energy production. By binding cardiolipin, SS-31 has been shown to help **stabilize mitochondrial membrane architecture, improve electron transport chain efficiency, support ATP generation, and reduce excessive reactive oxygen species formation**. Unlike many peptides, its activity is not centered on a classic cell-surface receptor. Instead, its mechanism is best described as **targeting mitochondrial membrane biology and bioenergetic function**. This mechanism is especially relevant in disorders involving **mitochondrial dysfunction and abnormal cardiolipin biology**, which is why elamipretide was ultimately developed most successfully in **Barth syndrome**. ## Evidence Summary SS-31 has a substantial preclinical literature showing effects on **mitochondrial function, oxidative stress, bioenergetics, and tissue protection** across multiple organ systems. Mechanistic studies strongly support its cardiolipin-directed mitochondrial activity. Human clinical evidence is more mixed and indication-specific. In **Barth syndrome**, a phase 2/3 clinical trial followed by an open-label extension reported improvements in several functional outcomes over longer-term treatment. This development pathway ultimately led to **FDA accelerated approval in 2025** as Forzinity for improvement of muscle strength in patients with Barth syndrome weighing at least 30 kg. By contrast, broader mitochondrial indications have not all produced positive confirmatory results. In **primary mitochondrial myopathy**, the MMPOWER-3 phase 3 trial reported that elamipretide did **not** significantly improve the primary functional endpoints at 24 weeks versus placebo. This makes SS-31 a good example of a peptide with a **strong mechanism, mixed broader clinical outcomes, and one narrow FDA-approved indication** rather than a universally proven mitochondrial therapy. ## Key References - Birk AV, et al. [*The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin.*](https://pubmed.ncbi.nlm.nih.gov/23813215/) **Journal of the American Society of Nephrology.** 2013. - Thompson WR, et al. [*A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome.*](https://pubmed.ncbi.nlm.nih.gov/33077895/) **Genetics in Medicine.** 2021. - Karaa A, et al. [*The MMPOWER-3 Randomized Clinical Trial: Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy.*](https://pubmed.ncbi.nlm.nih.gov/37268435/) **Neurology.** 2023. - Thompson WR, et al. [*168-week open-label extension results of TAZPOWER.*](https://pubmed.ncbi.nlm.nih.gov/38602181/) **Molecular Genetics and Metabolism.** 2024. - U.S. Food and Drug Administration. [*FDA Grants Accelerated Approval to First Treatment for Barth Syndrome.*](https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-first-treatment-barth-syndrome) **FDA.** 2025. ## Last Scientifically Reviewed September 4, 2026 ## Quick Definition SS-31 is a mitochondria-targeted tetrapeptide studied for its effects on cardiolipin stabilization, mitochondrial bioenergetics, oxidative stress modulation, and mitochondrial disease-related dysfunction. ## Targets / Receptors Cardiolipin binding; inner mitochondrial membrane stabilization; electron transport chain support; ATP production; oxidative stress modulation; mitochondrial bioenergetics; skeletal muscle energy metabolism ## Safety & Limitations SS-31 is now **FDA approved in a narrow indication**, but that does **not** mean it is broadly validated for all mitochondrial, longevity, or recovery-related uses. Its approved use is specifically tied to **Barth syndrome** in patients meeting the labeled criteria. Outside that approved indication, the evidence base is more limited and mixed. Some clinical programs have shown encouraging findings, while others, including a phase 3 study in **primary mitochondrial myopathy**, failed to meet key efficacy endpoints. This means broader claims should be made cautiously. The most commonly reported adverse events in clinical trials were **injection-site reactions**, which were generally mild to moderate. Serious reactions have also been reported. Long-term benefits and risks outside the approved indication remain less well established than many marketing claims suggest. ## Frequently Asked Questions - ### What is SS-31? SS-31, also known as elamipretide, is a mitochondria-targeted tetrapeptide designed to interact with cardiolipin in the inner mitochondrial membrane and support mitochondrial function. - ### What does SS-31 target? SS-31 primarily targets cardiolipin and inner mitochondrial membrane function rather than a traditional cell-surface receptor. - ### What is SS-31 being researched for? SS-31 has been studied in mitochondrial dysfunction, oxidative stress, skeletal muscle performance, bioenergetics, Barth syndrome, primary mitochondrial myopathy, and other mitochondrial-related disorders. - ### Is SS-31 FDA approved? Yes. As Forzinity (elamipretide), it received FDA accelerated approval in 2025 for improvement of muscle strength in patients with Barth syndrome weighing at least 30 kg. - ### Is SS-31 approved for anti-aging or general wellness use? No. SS-31 is not FDA approved for general anti-aging, performance, recovery, or broad wellness use. ## Available Research Compound - [Product page](https://chooseunscripted.com/shop/ss-31/index.md)