SS-31 (Elamipretide) Research Peptide

What Is SS-31?

SS-31 is a four-amino-acid peptide designed to reach the inside of mitochondria. Its name comes from Hazel Szeto and Peter Schiller, whose “Szeto-Schiller” peptides share an alternating pattern: positive charge, aromatic ring, positive charge, aromatic ring. In SS-31, D-arginine and lysine supply the positive charges, and Dmt and phenylalanine supply the aromatic rings. That pattern lets the peptide cross cell membranes and concentrate at the inner mitochondrial membrane.

There, SS-31 binds cardiolipin, the phospholipid that holds the inner membrane in its folded shape (cristae) and anchors the protein complexes that make ATP. Published studies report that SS-31 helps preserve cristae structure and inhibits cytochrome c’s peroxidase activity, a reaction that damages cardiolipin. The Dmt residue, a modified tyrosine, is the part of the molecule linked to scavenging reactive oxygen species.

SS-31 has an unusually deep clinical record for a research peptide. As elamipretide, it went through Phase 2 and Phase 3 trials in Barth syndrome, primary mitochondrial myopathy and dry age-related macular degeneration, and in 2025 the FDA approved it as Forzinity for Barth syndrome. The research-grade SS-31 sold here is not that drug. For related research compounds, see peptides for longevity research.

This product is strictly for research purposes only. Not approved for human or animal use.

Key Characteristics

Molecular Profile

Physical Properties

SS-31 in Published Research

Preclinical research on SS-31 is broad. Studies have examined its effects on mitochondrial membrane potential, ATP production and oxidative stress in models of heart failure, kidney injury from interrupted blood flow, skeletal muscle and the brain. One frequently cited rat study reported that pretreatment protected cristae membranes during kidney ischemia and prevented mitochondrial swelling.

The clinical record is mixed, and worth reading honestly. Some trials of elamipretide missed their primary endpoints, including studies in primary mitochondrial myopathy. In Barth syndrome, the FDA granted accelerated approval in September 2025 based on improved knee-extensor muscle strength, an intermediate endpoint, and required a confirmatory trial to show that it translates into patient benefit.

That combination, broad preclinical data plus a real but limited clinical success, is what makes SS-31 a reference compound in mitochondrial research rather than a universally validated one. Every lot is verified by HPLC and mass spectrometry; because SS-31 contains two non-standard residues, the mass check is especially important. See how to read a peptide COA.

Frequently Asked Questions

What is SS-31 studied for?

Mitochondrial dysfunction, through its binding to cardiolipin in the inner mitochondrial membrane. Research models include heart failure, kidney ischemia-reperfusion injury and age-related mitochondrial decline.

Is SS-31 the same as elamipretide?

Yes. SS-31, elamipretide, MTP-131 and Bendavia are names for the same molecule.

Is SS-31 FDA approved?

Elamipretide received FDA accelerated approval on September 19, 2025, as Forzinity for Barth syndrome. Research-grade SS-31 is not that approved drug and is for laboratory use only.

What do the clinical trials show?

Mixed results. Some trials missed their primary endpoints, while the Barth syndrome program showed improved muscle strength and led to accelerated approval, with a confirmatory trial required.

What does SS stand for?

Szeto-Schiller, after Hazel Szeto and Peter Schiller, who developed this family of mitochondria-targeting peptides.

How should SS-31 be stored?

Refrigerated at 2–8 °C (36–46 °F), sealed, dry and away from light. For long-term storage, −20 °C. Available in 10 mg and 50 mg options, 10 vials per kit.