SS-31
SS-31 (elamipretide) is a synthetic tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2, from the Szeto-Schiller peptide family that is designed to concentrate in mitochondria.
- TypePeptide
- FormulaC32H49N9O5
- Average mass639.79 g/mol
- CAS736992-21-5
- Vesta listings3
Reference page for laboratory use · updated 2026-10-30
Overview
SS-31 at a glance
Dmt stands for 2',6'-dimethyltyrosine. The peptides of this family have alternating aromatic and positively charged residues and interact with cardiolipin in the inner mitochondrial membrane, as set out in review articles on elamipretide's structure and mechanism.
In research it is used in mitochondrial dysfunction models in cells and animals.
Structure
The molecule contains a D-arginine, a non-natural dimethyltyrosine and a C-terminal amide. The sequence-based formula matches PubChem exactly.
Identity
Identity data
| Name | SS-31 |
|---|---|
| Also written as | Elamipretide, MTP-131 |
| Type | Peptide |
| Research area | Mitochondria-related peptides |
| Molecular formula | C32H49N9O5 |
| Monoisotopic mass | 639.3857 Da |
| Average molecular weight | 639.79 g/mol |
| CAS number | 736992-21-5 |
| Sequence | Arg-Dmt-Lys-Phe-NH2 |
| PubChem record | CID 11764719 |
The formula was calculated independently from the written sequence and matches the PubChem record exactly. Reference data retrieved on 2026-10-30. Compare these values with the batch certificate of analysis, using the compound identity file template.
Expected values
Mass spectrometry reference
Ions calculated from the monoisotopic mass 639.3857 Da. Use them to check an LC-MS result; for larger peptides the instrument usually reports a deconvoluted mass close to 639.8 Da instead.
| Ion | m/z |
|---|---|
| [M+H]+ | 640.3930 |
| [M+2H]2+ | 320.7001 |
| [M+Na]+ | 662.3749 |
| [M+K]+ | 678.3489 |
Read the guide to average and monoisotopic mass for how these values are calculated.
Quality
Analytical notes for batch documents
- At 639.8 Da the main ion is [M+H]+ at m/z 640.39; because it has two basic side chains a [M+2H]2+ ion at m/z 320.70 is also strong.
- D-amino acids do not change the mass, so enantiomeric purity is not shown by routine LC-MS.
- No residue in this sequence is especially prone to oxidation or deamidation, so most extra peaks are likely to be synthesis-related impurities or adducts.
- The molecular weight of a vial of powder includes counter-ions and water; the share of the powder that is peptide is the net peptide content.
Terms used on this page: D-amino acid.
Vesta listings
SS-31 formats and prices
| Product | Per vial | SKU | Price per kit | Price per vial |
|---|---|---|---|---|
| SS-31 | 5 mg | 2S5 | $67.16 | $6.72 |
| SS-31 | 10 mg | 2S10 | $104.48 | $10.45 |
| SS-31 | 50 mg | 2S50 | $354.48 | $35.45 |
Prices are per kit of 10 vials in US dollars. Shipping is paid by the customer and is shown in the cart. Volume savings of 5 %, 8 % and 10 % apply from $350.00, $600.00 and $1,000.00. See the full price list.
Published literature
Selected scientific literature
Bibliographic details were read from PubMed on 2026-10-30. The papers are listed for scientific reference; Vesta makes no claim about the use of its research materials in people or animals.
- Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic PotentialTung C, Varzideh F, Farroni E et al. · Int J Mol Sci · 2025 · PMID 39940712
- Targeting mitochondrial dysfunction with elamipretideObi C, Smith AT, Hughes GJ et al. · Heart Fail Rev · 2022 · PMID 35037146
Questions
Frequently asked questions
What is SS-31?
SS-31 (elamipretide) is a synthetic tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2, from the Szeto-Schiller peptide family that is designed to concentrate in mitochondria.
What is the molecular weight of SS-31?
SS-31 has the formula C32H49N9O5, an average molecular weight of 639.79 g/mol and a monoisotopic mass of 639.3857 Da. A salt form, a different counter-ion or a metal complex changes the molecular weight printed on a certificate of analysis, so compare like with like.
How can I check the identity of a batch of SS-31?
Compare the intact mass measured by LC-MS with the expected values on this page, for example [M+2H]2+ at m/z 320.7001. Confirm that one main HPLC peak carries that mass and that the batch code on the report matches the vial. The guides on mass spectrometry and on certificates of analysis explain each step.
Which SS-31 products does Vesta list?
Vesta lists 3 products for SS-31: 5 mg, 10 mg, 50 mg per vial in kits of 10 vials. Prices are shown per kit in US dollars, and shipping is paid by the customer.