SS-31 / Elamipretide

01 / Dosing schedule

Cited dosing

Elamipretide is the most rigorously dosed peptide on this list: 40 mg once daily subcutaneously in a 218-participant phase 3 trial in primary mitochondrial myopathy and in the phase 2/3 TAZPOWER crossover trial in Barth syndrome. It is not approved for mitochondrial myopathy; a Barth syndrome product (Forzinity) later reached the US market at the same 40 mg once-daily dose.

Elamipretide 40 mg/day subQ — MMPOWER-3 and TAZPOWER

Phase	Dose & frequency
MMPOWER-3 dose	40 mg/day elamipretide subcutaneously, once daily
MMPOWER-3 duration	24 weeks double-blind; assessments at weeks 4, 12 and 24
MMPOWER-3 administration	self-administered subcutaneously by trained participants or caregivers
TAZPOWER dose	40 mg once daily subcutaneously for 12 weeks, 4-week washout, then crossover
TAZPOWER extension	40 mg once daily open-label for up to an additional 168 weeks (10 of 12 patients)
FDA advisory-committee document dose scaling	20-30 mg/day for a 70 kg person from animal-model exposure; 0.25-0.5 mg/kg/day used in children >12 y in an expanded-access programme

Source · 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. ↗

Source indication · Primary mitochondrial myopathy (MMPOWER-3, NCT03323749) and Barth syndrome cardiomyopathy (TAZPOWER)

Injection frequency: Once daily, every day. 24 weeks in MMPOWER-3; 12-week periods with a 4-week washout in TAZPOWER, extending to 168-196 weeks open-label.
Injection sites: MMPOWER-3 protocol: rotating sites around the four quadrants of the abdomen, and the thighs.

02 / Reconstitution

Reconstitution reference

Trial product was a subcutaneous injection self-administered by participants; the cited publications do not describe participant-level reconstitution. The marketed Barth syndrome presentation is listed on DailyMed as 280 mg/3.5 mL (80 mg/mL) solution for subcutaneous use.

Vial280 mg/3.5 mL (80 mg/mL) per the marketed subcutaneous presentation

BAC watern.a. — solution, not lyophilised powder

Concentration80 mg/mL

Example dose40 mg once daily

On a U‑100 syringe0.5 mL of an 80 mg/mL solution

Open the reconstitution calculator →

03 / Overview

Protocol overview

Elamipretide (SS-31, MTP-131) is a mitochondria-targeting tetrapeptide that associates with cardiolipin in the inner mitochondrial membrane. Every controlled human trial fetched for this page used the same dose: 40 mg once daily by subcutaneous injection.

MMPOWER-3 was a 24-week randomized, double-blind, placebo-controlled phase 3 trial of 218 adults with genetically confirmed primary mitochondrial myopathy at 27 centres in seven countries. Participants or caregivers self-injected 40 mg/day, rotating sites across the four abdominal quadrants and thighs.

TAZPOWER was a phase 2/3 randomized double-blind placebo-controlled crossover trial in 12 male patients with genetically confirmed Barth syndrome (mean age 19.5 years): 40 mg/day for 12 weeks, a 4-week washout, then crossover, followed by an open-label extension of up to 168 additional weeks. Injection-site reactions were the dominant adverse event and caused two withdrawals by week 24 of the extension.

The FDA cardiovascular and renal drugs advisory committee briefing package for elamipretide notes that the animal-model exposures correspond to roughly 20-30 mg/day in a 70 kg adult, consistent with the 40 mg clinical dose, and that paediatric expanded-access dosing ran 0.25-0.5 mg/kg/day. No human elimination half-life is stated in any of the trial or FDA documents fetched here, so half-life is recorded as n.a.

04 / References