Mitochondrial / Barth syndrome
Prepared by the ezGLP team. Sources last checked . Profile reviewed .
Also known as Elamipretide, MTP-131, Forzinity
Routes represented in the knowledgebase: Subcutaneous (SubQ).
SS-31 is listed in the ezGLP knowledgebase under Mitochondrial / Barth syndrome. Evidence and regulatory status can vary by formulation, route, and jurisdiction.
SS-31, known generically as elamipretide and formerly as MTP-131 or Bendavia, is a synthetic tetrapeptide (D-Arg-dimethylTyr-Lys-Phe-NH2) that concentrates in the inner mitochondrial membrane and binds reversibly to cardiolipin, a phospholipid needed for electron-transport-chain assembly. It is classed as a mitochondria-targeted peptide; the FDA label describes it as a mitochondrial cardiolipin binder. Proposed effects, drawn largely from cell and animal work, include stabilized cristae structure, improved ATP production, and reduced production of reactive oxygen species under stress. It was developed by Stealth BioTherapeutics from a series of Szeto-Schiller peptides, which is the origin of the SS designation.
Elamipretide has a real clinical trial record, which distinguishes it from most peptides in this category. Animal models of ischemia-reperfusion, heart failure, kidney injury, and aging muscle produced encouraging results, but several human programs did not. Trials in heart failure, acute kidney injury after angioplasty, and primary mitochondrial myopathy missed their primary endpoints. In Barth syndrome, the TAZPOWER trial randomized 12 males in a placebo-controlled crossover design; neither primary endpoint was met, while the open-label extension of up to 168 weeks reported improved walking distance and knee extensor strength against natural-history controls. Injection-site reactions were the most common adverse events.
In September 2025 the FDA granted accelerated approval to elamipretide under the brand name Forzinity, a subcutaneous injection, to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg, based on knee extensor strength as an intermediate endpoint and contingent on confirmatory evidence. Barth syndrome affects roughly 150 people in the United States. The product has orphan designation from the European Medicines Agency but no EU marketing authorization as of this review. Any other use, including wellness or longevity marketing of SS-31 as a research peptide, is unapproved and lies outside the label. SS-31 is not named on the WADA Prohibited List.
Forzinity is supplied as a single-patient-use vial of solution for subcutaneous injection. The label states that unopened vials are refrigerated at 2 to 8 degrees Celsius and not frozen, that an opened vial may be kept refrigerated or at room temperature, and that vials are discarded 8 days after first opening. Research-grade SS-31 sold as lyophilized powder has no such label, so its storage and beyond-use time are unverified. A dose log for elamipretide commonly records vial lot, date the vial was first opened, injection site, and any injection-site reaction, which is the effect most often reported in trials. An inventory record tied to vial opening dates supports the 8-day discard rule.
No verified PubMed or DOI link is available for this entry.
Common or reported: injection-site redness, pain, firmness, itching, or bruising, eosinophilia.
Serious or important: hypersensitivity.
The approved Barth-syndrome safety dataset was small.
Safety evidence sourceThese are general, pairwise evidence notes. Green identifies the potential-synergy category, while Lv3/Lv2/Lv1 communicates evidence strength; it does not guarantee benefit or cancel a safety warning.
SS-31 plus the NAD+ precursor NMN produced complementary cardiac effects in aged mice, providing an indirect rationale for interest in SS-31 with NAD+.
Interaction evidence sourceNAD+ evidence reviewElamipretide labelYes, narrowly. On September 19, 2025, the FDA granted accelerated approval to elamipretide as Forzinity to improve muscle strength in people with Barth syndrome weighing at least 30 kg, an ultra-rare mitochondrial disease. Approval rested on an intermediate endpoint, knee extensor strength, and continued approval depends on confirmatory trials. No other indication is approved, and research-grade SS-31 sold online is not the approved product.
Not shown. Animal studies of aged muscle and heart reported improved mitochondrial function, but human trials in heart failure, kidney injury, and primary mitochondrial myopathy failed to meet primary endpoints. The only approval concerns Barth syndrome, where the randomized phase also missed its primary endpoints and benefit was inferred from long-term open-label data. Claims about longevity or general mitochondrial enhancement in healthy people have no trial support.
The FDA label for Forzinity reports an elimination half-life of roughly four hours after subcutaneous injection, with once-daily administration in the trials. Elamipretide is cleared mainly by peptide hydrolysis and renal excretion rather than cytochrome P450 metabolism, so drug interactions through liver enzymes are considered unlikely. Pharmacokinetic figures apply to the approved formulation, not to unverified research-grade powder.
According to the label, unopened vials are kept refrigerated at 2 to 8 degrees Celsius in the original carton and not frozen. After the first dose is drawn, the vial may be stored either refrigerated or at room temperature, and it is discarded 8 days after first opening regardless of remaining volume. The product is a ready-to-use solution and is not reconstituted. Research-grade SS-31 powder has no comparable stability data.
Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.
For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live. Consult a licensed healthcare professional.
