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Ouralusouralus
Compound reference

SS-31: identity, research literature, and verified purity

99.717%assayed by HPLC at Janoshik

SS-31 vial

The lot currently shipping assayed 99.717% by third-party HPLC at Janoshik, and that certificate is published here with a key you can confirm with the laboratory yourself.

Identity and registry data

CAS
736992-21-5
Molecular formula
C32H49N9O5
Molar mass
639.8 g/mol
Sequence
H-D-Arg-Dmt-Lys-Phe-NH2
PubChem CID
11764719
UNII
87GWG91S09

Also known asElamipretide · MTP-131 · Bendavia · Szeto-Schiller peptide 31

What the research literature covers

The characterization below reflects published research literature only. It describes what that literature examines; it is not a statement about use in people. SS-31 is investigational research material and is not an approved product.

SS-31 is a synthetic tetrapeptide — D-Arg-Dmt-Lys-Phe-NH2, in which Dmt is 2,6-dimethyltyrosine — supplied as a lyophilized powder for laboratory research use only. It appears in the literature under the name elamipretide and under the development codes MTP-131 and Bendavia.

Its alternating aromatic and cationic residues give it a charge-and-hydrophobicity profile that the mechanistic literature describes as concentrating the peptide at the inner mitochondrial membrane without depending on membrane potential, which is the structural feature most of that work is concerned with.

The reported interactions center on cardiolipin, a phospholipid largely confined to the inner mitochondrial membrane. Biophysical work characterizes binding to lipid bilayers and modulation of membrane surface electrostatics; chemical-crosslinking mass spectrometry has been used to map which mitochondrial proteins sit within range of the bound peptide.

Structure-activity work across related tetrapeptide analogues examines which residues account for the observed membrane association. The literature listed below is in-vitro, cell-free, and preclinical: it reports binding measurements and bioenergetic readouts in isolated systems.

Reported mechanism · literatureIn the mechanistic literature SS-31 is characterized as a mitochondria-targeting tetrapeptide that associates with cardiolipin in the inner mitochondrial membrane and alters the local lipid environment and surface charge, with reported consequences for the organization of electron-transport components as measured in isolated mitochondria and in cell-free bilayer systems.

  • Mitochondrial biology
  • Cytoprotection

Purity, and how to check it yourself

Purity here is a measurement, not a position. The lot currently shipping was analysed by Janoshik, an independent laboratory, by HPLC for identity and assayed purity. We do not test our own material.

Lot
Blue Cap
Analysed
December 15, 2025
Assayed purity
99.717%
Testing laboratory
Janoshik
Verify key
XLC46CAH4U1N

Enter that key at janoshik.com/verify and the laboratory returns the report it issued for this batch. You are confirming the result with them, not with us. The full certificate is published as a PDF on the SS-31 certificate page.

We report HPLC identity and assayed purity only. We do not run heavy-metal, microbial, endotoxin, or sterility analysis, and we do not claim it anywhere on this site.

Handling and stability

Lyophilized
−20°C · sealed, desiccated; protect from light

Questions

What is SS-31?

SS-31 is a synthetic tetrapeptide with the sequence D-Arg-Dmt-Lys-Phe-NH2, where Dmt is the non-standard residue 2,6-dimethyltyrosine. It is also known as elamipretide, MTP-131, and Bendavia. Ouralus supplies it as a lyophilized powder for laboratory research use only.

What is the molecular formula of SS-31?

C32H49N9O5 (molar mass ≈ 639.8 g/mol; PubChem CID 11764719, CAS 736992-21-5, UNII 87GWG91S09). The alternating aromatic and basic residues, and the C-terminal amide, are what distinguish it from a conventional linear tetrapeptide.

Is SS-31 third-party tested?

Yes. The lot currently shipping was analysed by Janoshik, an independent laboratory, by HPLC for identity and assayed purity, and assayed 99.717%. The certificate carries verify key XLC46CAH4U1N, which you can confirm directly at janoshik.com/verify.

Is SS-31 an approved product?

No. SS-31 is supplied strictly as a research chemical for laboratory research use only. It is not a drug, not a supplement, and not a food, and it is not for human or animal consumption.

Questions answered from the cited research

Selected literature

  1. The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipinBirk AV, et al. · Journal of the American Society of Nephrology · 2013PMID 23813215 ↗
  2. The mitochondria-targeted peptide SS-31 binds lipid bilayers and modulates surface electrostatics as a key component of its mechanism of actionMitchell W, et al. · Journal of Biological Chemistry · 2020PMID 32273339 ↗
  3. Mitochondrial protein interaction landscape of SS-31Chavez JD, et al. · Proceedings of the National Academy of Sciences · 2020PMID 32554501 ↗
  4. Structure-activity relationships of mitochondria-targeted tetrapeptide pharmacological compoundsMitchell W, et al. · eLife · 2022PMID 35913044 ↗

Research-literature characterization, provided for research context only. For laboratory research use only. Not for human consumption.