Research reference, direct numbers first, from clinical-trial literature: Across human trials, subcutaneous elamipretide (SS-31) has most often been studied at 40 mg once daily — the dose used in the TAZPOWER Barth-syndrome trial and in heart-failure work. Single subcutaneous doses in pharmacology studies ranged from 2 mg to 80 mg; its plasma half-life is roughly 2 hours.
A note on sourcing: because SS-31 is an actively studied investigational drug, the numbers and claims below are drawn from published clinical trials and regulatory records rather than forum reports. Where human evidence is mixed or absent, we say so.
What SS-31 Is
SS-31 — elamipretide, also known historically as Bendavia and MTP-131 — is a synthetic, water-soluble, aromatic-cationic tetrapeptide (sequence D-Arg-Dmt-Lys-Phe-NH2). Its defining feature is that it is mitochondria-targeting: its net positive charge draws it to the inner mitochondrial membrane, where it binds selectively to cardiolipin, a phospholipid found almost exclusively there. Cardiolipin is essential for maintaining the folded cristae architecture of the inner membrane and for the proper function of the electron transport chain. By stabilizing cardiolipin, SS-31 is proposed to preserve electron-transport efficiency, reduce reactive oxygen species production at their source, and improve ATP synthesis — acting upstream of the damage rather than scavenging free radicals after the fact.
What the Clinical Trials Actually Show
This is where discipline matters, because the trial record is genuinely mixed:
- Barth syndrome (TAZPOWER, NCT03098797): a phase 2/3 crossover trial of 40 mg/day subcutaneous elamipretide. Benefit on the six-minute walk test accrued over longer open-label treatment, and this program ultimately supported the 2025 accelerated approval for Barth syndrome. This is the compound’s strongest human evidence.
- Heart failure (PROGRESS / HFpEF and HFrEF work): early studies showed elamipretide was well tolerated and, at the highest infusion dose, reduced left-ventricular volumes; a phase 1/2 study in 36 HFrEF patients found significant reductions in end-diastolic and end-systolic volume. However, the broader heart-failure and primary-mitochondrial-myopathy efficacy trials did not meet their primary endpoints — cardiovascular benefits remain an active area of research.
- Primary mitochondrial myopathy: a dose-escalation trial supported the proposed ATP-synthesis mechanism and a high-dose subcutaneous arm showed a dose-dependent six-minute-walk signal, but later confirmatory efficacy work was disappointing.
- Healthy aging: as of 2025–2026 this is being examined in small early-phase studies (for example, the SHAPE pilot in older adults) — meaning general “anti-aging” use is an exciting area still under investigation.
Safety across roughly 200 subjects in completed pharmacology studies has been reasonable: the most common systemic adverse event was headache (~7%), with nausea and, in some settings, hyponatraemia each around 3%, and no pattern of serious adverse events over short-term dosing. “Well tolerated” is well supported; “broadly effective” is not.
Dosing as Reported in Trials
- Subcutaneous: 40 mg once daily is the most frequently studied regimen; single-dose SC studies spanned 2–80 mg.
- Intravenous: infusion studies used weight-based rates (e.g., 0.005–0.25 mg/kg/hour over several hours) in controlled clinical settings.
- Half-life: approximately 2 hours after subcutaneous dosing, with peak concentration at 1–2 hours — consistent with once-daily use.
We are intentionally not publishing a reconstitution-and-syringe “protocol” for SS-31 the way a research vial vendor might. Elamipretide is an approved drug for one specific indication and an investigational agent for everything else; its clinically studied dosing was delivered under trial supervision (and the approved product is a formulated solution, not a lyophilized research vial). Presenting a do-it-yourself dosing recipe would misrepresent where the evidence actually sits.
Cautions
Elamipretide’s only approved use is Barth syndrome, and even that approval is accelerated — meaning continued approval depends on confirmatory benefit. For other purposes it remains investigational, and researchers continue to study where it helps most beyond Barth syndrome. Anyone considering it should do so only under a licensed physician who can weigh the actual trial evidence against the specific clinical situation.
Key References
- Reid Thompson W, Hornby B, Manuel R, et al. Elamipretide in Barth syndrome (TAZPOWER). Genet Med. 2021;23(3):471–478.
- Daubert MA, et al. Elamipretide in HFpEF: the PROGRESS trial. JACC Heart Fail. 2017;5(9):631–643.
- Szeto HH. First-in-class cardioprotective agent SS-31 targeting mitochondrial cardiolipin. Future Med Chem. 2015;7(2):201–216.
- Stealth BioTherapeutics. FORZINITY (elamipretide) — accelerated approval, September 2025.
This article is a research reference, not medical advice. Flow BioLabs does not provide prescriptions or dosing directions. Any decision to use this compound should be made with your own licensed physician. Explore how Flow BioLabs evaluates peptide evidence in our education library.
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