Last reviewed: October 2026 · Cleared Peptides research team
SS-31, also known as elamipretide (MTP-131), is a synthetic aromatic-cationic tetrapeptide from the Szeto–Schiller (SS) peptide series. It selectively associates with the inner mitochondrial membrane, where it interacts with the phospholipid cardiolipin, making it a standard tool compound in mitochondrial biochemistry.
In this guide:
- Structure and identifiers
- Design: alternating aromatic and cationic residues
- In-vitro research areas
- FAQ
SS-31 Structure and Identifiers
| Name | SS-31 (elamipretide) |
|---|---|
| Synonyms | MTP-131; Bendavia |
| CAS number | 736992-21-5 |
| PubChem CID | 11764719 |
| Molecular formula | C32H49N9O5 |
| Molecular weight | ≈639.8 g/mol |
| Sequence | D-Arg-Dmt-Lys-Phe-NH2 (Dmt = 2′,6′-dimethyltyrosine) |
| Form | Lyophilized powder |
Design: Alternating Aromatic and Cationic Residues
SS peptides alternate aromatic and basic residues, giving a +3 net charge at physiological pH while remaining cell-permeable. The D-arginine at position 1 confers resistance to aminopeptidases, and the dimethyltyrosine residue contributes to its membrane interaction. These features let SS-31 concentrate at the inner mitochondrial membrane independently of membrane potential.
Published In-Vitro Research Areas
- Cardiolipin binding and inner-membrane structure studies
- Electron-transport-chain and cytochrome c peroxidase activity assays
- Reactive-oxygen-species production in isolated mitochondria
- Comparative studies with mitochondrial-derived peptides such as MOTS-c
This summary describes laboratory research only and makes no claim about effects in humans or animals.
Research formats: SS-31 (Elamipretide) and the MOTS-c + SS-31 research set. Lot COAs are on our COA page.
Research materials referenced in this guide
Frequently Asked Questions
Is SS-31 the same as elamipretide?
Yes. SS-31 is the original research code; elamipretide is the nonproprietary name (CAS 736992-21-5).
What does SS-31 bind to?
In laboratory studies SS-31 associates with cardiolipin, a phospholipid of the inner mitochondrial membrane.
Is SS-31 for human use?
No. It is supplied for laboratory research use only.
Selected References
Peer-reviewed literature on the compounds discussed in this guide, listed as scientific background for laboratory researchers. Citation does not imply endorsement by the authors or any use other than in-vitro research.
- Chavez JD, et al. Mitochondrial protein interaction landscape of SS-31. Proc Natl Acad Sci U S A. 2020;117(26):15363-15373. PubMed 32554501 · DOI
Laboratory note: solubility depends on salt form and solvent. This guide does not state a single solubility figure. Handling of lyophilized material is described in the peptide storage guide.
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published, primarily in-vitro and structural research literature and does not describe, recommend or imply any use in humans or animals. Products sold by Cleared Peptides are for laboratory research use only; they are not drugs, foods, cosmetics or dietary supplements, are not FDA-approved, and are not intended to diagnose, treat, cure, mitigate or prevent any disease. No dosing, administration or therapeutic information is provided.
