SS-31
Elamipretide (Szeto-Schiller-31)
aka Elamipretide · Forzinity · MTP-131 · Bendavia · SS-31 peptide
A mitochondria-targeting peptide researched for reducing oxidative stress and improving cellular energy metabolism.
Sequence
Mechanism of action
SS-31 is a mitochondria-targeting peptide that selectively binds to cardiolipin, a lipid unique to the inner mitochondrial membrane. By stabilizing cardiolipin, SS-31 helps maintain mitochondrial structure and function, reducing the production of reactive oxygen species. This action decreases oxidative stress and enhances ATP production, thereby improving cellular energy metabolism.
What the evidence actually shows
FDA APPROVED (September 2025) as Forzinity for Barth syndrome. First FDA-approved mitochondria-targeted therapeutic.
Regulatory status
In the UK, SS-31 is considered a research compound and is not approved for clinical use by the MHRA.
Source ↗Pharmacokinetics
Dosing — what backs each figure
SS-31 (elamipretide) is FDA-approved as FORZINITY at 40 mg subcutaneously once daily for Barth syndrome patients weighing at least 30 kg, halved to 20 mg daily when eGFR is below 30 mL/min; the same 40 mg/day subcutaneous dose was used in the TAZPOWER Barth trial and in MMPOWER-3, which failed its primary endpoints in primary mitochondrial myopathy. Approval is accelerated and based on knee extensor muscle strength as an intermediate endpoint.
40 mg subcutaneously once daily at the same time each day (patients weighing 30 kg or more); reduce to 20 mg once daily if eGFR is below 30 mL/min and the patient is not on dialysis; injected into the abdomen or outer thigh with daily site rotation
adult and pediatric patients with Barth syndrome weighing at least 30 kg (accelerated approval based on improvement in knee extensor muscle strength) · subcutaneous
FDA label FORZINITY (elamipretide hydrochloride) injection, NDA 215244, initial US approval 2025 ↗
40 mg/day subcutaneously for 24 weeks (trial did not meet its primary endpoints)
adults with genetically confirmed primary mitochondrial myopathy (n=218), MMPOWER-3 phase 3 · subcutaneous
40 mg subcutaneously once daily continued through a 168-week open-label extension following a 28-week randomized placebo-controlled period
patients with Barth syndrome (n=10 entering the extension), TAZPOWER · subcutaneous
Handling and storage
No light-protection instruction appears in the FORZINITY prescribing information. Do not freeze.
Source ↗Safety
- ·Mild injection site reactions
- ·Allergic reactions
- ·Known hypersensitivity to SS-31
- ·Not characterised
Injection-site reactions
Reported combinations
- ·Coenzyme Q10
Combination claims in this dataset are largely unsourced and should be treated as folk knowledge until a citation appears beside them.
References (4)
- Thompson WR, Manuel R, Abbruscato A, Carr J, et al. (2024) Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. ↗Genetics in MedicinePMID 38602181DOI
168-week open-label extension of the TAZPOWER trial in Barth syndrome; the long-term dataset underpinning the accelerated approval of elamipretide.
- Karaa A, Bertini E, Carelli V, Cohen BH, et al. (2023) Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial. ↗NeurologyPMID 37268435DOI
Phase 3 randomised trial in primary mitochondrial myopathy; elamipretide did not meet its co-primary endpoints in this indication.
- Whitson JA, Martin-Perez M, Zhang T, et al. (2021) Elamipretide (SS-31) treatment attenuates age-associated post-translational modifications of heart proteins. ↗GeroSciencePMID 34480713DOI
Aged-mouse study showing elamipretide reverses age-associated post-translational modification of cardiac proteins, supporting the cardiolipin-binding mechanism.
- Karanjia R, Sadun AA (2024) Elamipretide Topical Ophthalmic Solution for the Treatment of Subjects with Leber Hereditary Optic Neuropathy: A Randomized Trial. ↗OphthalmologyPMID 37923251DOI
Randomised trial of topical ophthalmic elamipretide in Leber hereditary optic neuropathy.
Data provenance
Chemistry and citations on this page were checked against primary sources on 2026-08-14. Values that could not be verified were left blank rather than filled with a plausible guess.
Could not verify
regulatory.wada, storage.lightSensitive