SS-31 (Elamipretide)

How does SS-31 work?

SS-31 (elamipretide) is a cell-penetrating aromatic-cationic tetrapeptide that targets the mitochondrion directly. Its defining property is selective accumulation in the inner mitochondrial membrane through affinity for the phospholipid cardiolipin, where it stabilizes the machinery of energy production. The cardiolipin-binding mechanism is well-characterized in preclinical work; the downstream effects below are drawn from that literature.

1. Cardiolipin Binding & Mitochondrial Targeting [3]. SS-31 accumulates selectively in the inner mitochondrial membrane through its affinity for the phospholipid cardiolipin — concentrating the peptide exactly where the respiratory chain operates.
2. Cristae & Supercomplex Stabilization [3]. By binding and stabilizing cardiolipin, SS-31 helps preserve cristae structure and the assembly of respiratory-chain supercomplexes.
3. Reduced Mitochondrial ROS and Preserved Membrane Potential [3]. It reduces mitochondrial reactive oxygen species production and helps preserve the mitochondrial membrane potential.
4. Improved ATP Production [3]. Stabilizing the respiratory chain improves ATP production in dysfunctional or aged mitochondria.
5. ADP Sensitivity via the Adenine Nucleotide Translocator [1]. In aged mitochondria, elamipretide improved ADP sensitivity through effects on the adenine nucleotide translocator (Pharaoh et al. 2023).

What is SS-31 researched for?

SS-31's evidence base splits sharply by context. Clinically, the FDA accelerated approval (as Forzinity) is for one ultra-rare disease — Barth syndrome — and rests on the TAZPOWER trial program. Everything broader — anti-aging, cardiac, metabolic, cognitive, and athletic-performance applications — is preclinical (rodent and in-vitro) or in unconfirmed development. The findings below should be read with that distinction in mind.

1. Barth Syndrome — FDA Approval (TAZPOWER) [5]. Reid Thompson et al. 2021 (PMID 33077895) reports the TAZPOWER trial: a randomized, double-blind, placebo-controlled crossover trial (12 subjects randomized to 40 mg/day elamipretide or placebo for 12 weeks each) followed by an open-label extension. The randomized crossover phase did not meet its primary endpoints (6-minute walk test, BTHS symptom scale); at 36 weeks in the open-label extension, both endpoints showed statistically significant improvement (6MWT +95.9m, p=0.024; BTHS-SA -2.1 points, p=0.031). This human RCT plus its open-label extension is the basis for the FDA accelerated approval as Forzinity. Additional indications, including dry age-related macular degeneration and primary mitochondrial myopathy, have been in development.
2. Aged Mitochondria — ADP Sensitivity [1]. Elamipretide improved ADP sensitivity in aged mitochondria via the adenine nucleotide translocator (Pharaoh et al. 2023). Preclinical.
3. Exercise Tolerance in Aging [2]. Intermittent elamipretide preserved exercise tolerance in aged female mice (Campbell et al. 2023). Preclinical.
4. Cognition & Sleep Deprivation [4]. Elamipretide improved learning and memory impairment caused by chronic sleep deprivation in mice (Zhang et al. 2024). Preclinical.
5. Mitochondrial Dysfunction (Review) [3]. A 2024 review summarizes SS-31's role in mitigating mitochondrial dysfunction across experimental models (Du et al. 2024).

How is SS-31 dosed?

There are two very different answers depending on which material is meant. The approved drug Forzinity has an FDA-approved clinical regimen for Barth syndrome. Research-grade SS-31 has no validated research-use dose.

Prof. Peptide reports what trials established and what research communities practice, labelled separately. Neither is a recommendation.

For the approved drug Forzinity, an FDA-approved dosing regimen exists for Barth syndrome — a weight-based, once-daily subcutaneous injection given under prescription to patients weighing at least 30 kg. The specific weight-based figures belong to the prescribing information and a treating clinician, not to this page, so none are reproduced here. For research-grade SS-31, there is no validated research-use dose; it is unapproved material handled in the laboratory. Researchers reconstitute lyophilized powder with bacteriostatic or sterile water (see storage below); any volume chosen is a generic handling convenience, not a dosing recommendation. Prof. Peptide deliberately does not publish an injectable mg or mg/kg schedule for research-grade SS-31 — none has been validated, and the research material is not the approved drug.

What are the side effects of SS-31?

The two materials must again be kept separate. For the approved drug Forzinity, the documented adverse-effect profile is established in its Barth-syndrome program and is detailed in the FDA prescribing information — that document, not this page, is the authoritative source for the drug's safety. For research-grade SS-31 used outside the approved indication, human safety is not established. This is unapproved, Research Use Only material and is not intended for human consumption; nothing here should be read as human-use guidance.

How should SS-31 be stored?

1. Research-grade SS-31 (lyophilized powder): reported stored cold and desiccated, protected from light, frozen at -20°C for long-term storage; 2–8°C is acceptable short-term.
2. Bacteriostatic or sterile water for injection is reported used, added slowly down the inside wall of the vial with a gentle swirl rather than shaking.
3. Reconstituted solution: refrigerate at 2–8°C and keep protected from light.
4. SS-31 is stored protected from light at all times, in the original packaging.
5. Discard if the solution is cloudy, discolored, or contains particles.
6. The approved drug Forzinity should be stored according to its FDA prescribing information, not these research-handling notes.

What are the limitations of SS-31 research?

This is the most important section to read carefully. The FDA approval is narrow, and almost everything else about SS-31 is earlier-stage than the marketing around it suggests.

SS-31 FAQ

References

1. Pharaoh G, et al. Elamipretide improves ADP sensitivity in aged mitochondria via the adenine nucleotide translocator. GeroScience. 2023;45:3529-3548. PMID 37462785. https://pubmed.ncbi.nlm.nih.gov/37462785/
2. Campbell MD, et al. Intermittent elamipretide preserves exercise tolerance in aged female mice. GeroScience. 2023;45:2245-2255. PMID 36840897. https://pubmed.ncbi.nlm.nih.gov/36840897/
3. Du X, et al. SS-31 in mitigating mitochondrial dysfunction (review). Mitochondrion. 2024;75:101846. PMID 38237649. https://pubmed.ncbi.nlm.nih.gov/38237649/
4. Zhang YM, et al. Elamipretide improves learning and memory impairment induced by chronic sleep deprivation in mice. Brain Behav. 2024;14:e3508. PMID 38688894. https://pubmed.ncbi.nlm.nih.gov/38688894/
5. 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. (TAZPOWER trial — basis for the FDA accelerated approval as Forzinity, September 19, 2025.) https://pubmed.ncbi.nlm.nih.gov/33077895/

Published Studies