Peptide
SS-31
Elamipretide (SS-31)
A four-amino-acid peptide that binds to cardiolipin on the inner mitochondrial membrane and appears to restore mitochondrial function. In late-stage clinical trials for rare mitochondrial diseases and heart failure.
Summary What is SS-31, and does it really help aging mitochondria? Show / hide ↓
SS-31, also called elamipretide, is a peptide, a small chain of amino acids with four building blocks. It attaches to cardiolipin, a special fat in mitochondria, the parts of cells that produce energy, and may protect them from oxidative stress, which is cell damage caused by unstable molecules. Animal studies suggest it can improve energy production and reduce cell damage, but animal results do not prove it helps people. Several human trials for rare mitochondrial diseases, heart problems, eye disease, and muscle disease have had mixed results, with some measures improving and others not. The US Food and Drug Administration rejected approval for one rare mitochondrial disease in 2023 because a small trial did not provide enough evidence of benefit. SS-31 has not been proven to slow normal aging and is not a legitimate supplement sold to consumers.
What this means for you: SS-31 is scientifically plausible, but human results are conflicting and it has not been shown to extend healthy lifespan. There is not enough evidence to buy it, and products advertised online may be fake or diverted from clinical use.
conflicting evidenceSS-31 sits in a peculiar corner of longevity research. It has a plausible mechanism, real human trials, one FDA rejection, and a large body of preclinical work — yet almost no one in the biohacking community talks about it, because you cannot buy it. The peptide binds cardiolipin, a lipid unique to the inner mitochondrial membrane, and appears to prevent the cardiolipin-cytochrome-c interaction that drives peroxidation during oxidative stress. In animals with heart failure, kidney injury, or age-related muscle loss, SS-31 improves ATP production and reduces reactive oxygen species without acting as a general antioxidant.
Human data is thin but not empty. Elamipretide has been tested in Barth syndrome (a rare mitochondrial cardiomyopathy), heart failure with preserved ejection fraction, dry AMD, primary mitochondrial myopathy, and Duchenne muscular dystrophy. Results have been mixed. Some endpoints move; some do not. The FDA rejected accelerated approval for Barth syndrome in 2023 citing insufficient efficacy evidence in a small trial, though the agency later held additional discussions about a resubmission.
Why the peptide matters for longevity is straightforward: mitochondrial dysfunction is one of the hallmarks of aging, and cardiolipin remodeling is one of the earliest measurable mitochondrial changes with age. If SS-31 or a successor can be shown to work in a broad aging population — not just people with a rare disease — it could become the first genuinely mitochondrion-targeted anti-aging drug with a regulatory path. That is a big if.
The compound is not sold as a research chemical the way BPC-157 or MOTS-c are. It is a controlled clinical asset. If you see it advertised on a research-chemical site, the product is either fake or diverted, and the safety and identity of what you actually receive are unknown.
Further reading
Curated external sources for a deeper dive. External links open in a new tab.
- Stealth BioTherapeutics announces Complete Response Letter for elamipretide (2023)
- Elamipretide for Barth syndrome cardiomyopathy: gradual rebuilding of a lost heart substrate (Reid Thompson et al.)
- SS-31 peptide reverses the age-associated decline in muscle mitochondrial function (Siegel et al., Aging Cell)