SS-31 (elamipretide): approved dosage in the US
Not a recommendation, not treatment guidance. This page shows only the dosing in the official product information, with sources. The dose is always decided by the doctor who prescribes the medicine. Fimea warns against using injectable peptides bought online: Fimea warning.
Source of the dosing: Forzinity (elamipretide), FDA prescribing information (FDA), date of the text 9/2025 [1]official
Forzinity (elamipretide) is a medicine approved in the United States for Barth syndrome. According to the prescribing information it is meant to improve muscle strength in adults and children who weigh at least 30 kg [1]official.
The approval is an accelerated approval: it rests on improved knee extensor muscle strength, and continued approval may depend on the result of a confirmatory trial [1]official.
Dosing in the product information
| Product and step | Indication | Dose | Frequency | Duration | Source and level |
|---|---|---|---|---|---|
| Forzinity (elamipretide), standard dose | Barth syndrome, adults and children weighing at least 30 kg | 40 mg under the skin | Once a day, at the same time each day | Not stated in the prescribing information | [1]official |
| Forzinity (elamipretide), severe kidney impairment | Adults with eGFR below 30 mL/min, not on dialysis | 20 mg under the skin | Once a day | Not stated in the prescribing information | [1]official |
Evidence levels: official = official product information · A = randomised human trial or meta-analysis · B = observational human study or case series · C = animal study · D = cell or laboratory study · E = not peer-reviewed
Notes
According to the prescribing information, adults with eGFR of 30 mL/min or more take the same 40 mg once a day. A missed dose is skipped, and a double dose is not taken [1]official.
The prescribing information covers only elamipretide given under the skin. Use into a vein is not approved, and the solution contains benzyl alcohol, which must not be given to newborns [1]official.
What points the other way or is uncertain
In the randomised crossover trial in Barth syndrome (12 patients, 40 mg a day), neither primary endpoint, the walk test or the symptom scale, improved over 12 weeks compared with placebo. Improvements were seen only in the open-label extension without a placebo group [2]A.
In primary mitochondrial myopathy, the randomised MMPOWER-3 trial of 218 patients with the same 40 mg daily dose did not improve walking distance or fatigue over 24 weeks compared with placebo [3]A.
- SS-31 (elamipretide): the full substance page
- SS-31 (elamipretide): why no calculator preset
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- All dose pages and calculators
Read the research yourself: sources
- U.S. Food and Drug Administration. FORZINITY (elamipretide) injection, for subcutaneous use. Prescribing information, NDA 215244 (Revised: 9/2025). FDA (Drugs@FDA)
- Reid Thompson W, Hornby B, Manuel R, et al. A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome, a genetic disorder of mitochondrial cardiolipin metabolism. Genet Med. 2021;23(3):471-478. PMID 33077895
- Karaa A, Bertini E, Carelli V, et al. Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial. Neurology. 2023;101(3):e238-e252. PMID 37268435
Elamipretide has no central EU marketing authorisation (EMA list, checked on 12 Oct 2026), so the dosing is from the US prescribing information. The date is the "Revised: 9/2025" printed on the document.
Content is general information about research, not medical advice. If you have symptoms, contact a healthcare professional.