What Is SS-31 (Elamipretide)?

SS-31 is a small synthetic peptide composed of four amino acid residues arranged in an alternating aromatic-cationic pattern: D-Arg-Dmt-Lys-Phe-NH2. This motif, alternating a basic residue with an aromatic one, is a defining structural feature of the Szeto-Schiller peptide series and is central to how the compound is described in the research literature. Dmt refers to 2,6-dimethyltyrosine, a modified amino acid that is not found in standard proteins but was designed into the sequence for this research program.

As a research compound, SS-31 is supplied as a lyophilized (freeze-dried) powder that is reconstituted before use, following the same general handling principles that apply to other small research peptides. Its small size and simple four-residue backbone make it comparatively stable and straightforward to work with relative to longer, more complex peptide sequences.

The mechanistic focus of SS-31 research is its interaction with cardiolipin, a phospholipid that is concentrated almost exclusively in the inner mitochondrial membrane. Published research describes SS-31 as having a high-affinity, selective interaction with cardiolipin, which is proposed to allow the peptide to concentrate at this specific membrane location rather than distributing broadly throughout the cell.

This targeting property is the basis for describing SS-31 as a mitochondria-targeting peptide in the literature. Researchers studying mitochondrial dysfunction and oxidative stress models have investigated whether this cardiolipin interaction is associated with effects on electron transport chain function, reactive oxygen species production, and membrane structure in cell and tissue preparations. These are proposed mechanisms under active study, not established facts about how the compound behaves outside a laboratory model.

SS-31 appears in the published preclinical literature primarily in models of mitochondrial dysfunction and oxidative stress. Research groups have examined it in ischemia-reperfusion injury models, where tissue is deprived of blood flow and then reperfused, a process associated with a burst of oxidative damage at the cellular level. These studies are typically conducted in isolated cells, isolated mitochondria, or animal models, not in human subjects.

Heart failure research is another prominent area in the SS-31 literature, given the high mitochondrial density of cardiac tissue and its dependence on efficient oxidative metabolism. Preclinical cardiac models have investigated whether cardiolipin-targeted intervention affects markers of mitochondrial function in these systems.

SS-31 has also been studied in the context of Barth syndrome, a rare genetic condition involving abnormal cardiolipin metabolism, in academic and clinical research settings. Its relevance to this specific condition follows directly from the compound's proposed cardiolipin-binding mechanism. As with all preclinical findings referenced in this overview, results in cell, tissue, or animal models describe behavior within those specific model systems and do not establish any effect in humans.

Under the name elamipretide, this same compound has been investigated in human clinical trials for select indications related to mitochondrial dysfunction. Clinical trial existence is a documented fact about the compound's development history in the pharmaceutical research literature, and it is mentioned here for that reason.

It is important to keep two things separate: the fact that elamipretide has entered human clinical trials as an investigational drug candidate, and the regulatory status of the research-use-only material sold on this site. Clinical trial participation does not mean elamipretide is an FDA-approved drug, and it does not change the RUO status of laboratory-grade SS-31. RUO material is sold exclusively for in-vitro and preclinical laboratory research and is not intended, labeled, or authorized for administration to humans or animals outside of a licensed clinical trial protocol.

SS-31 ships as a lyophilized powder and is reconstituted with bacteriostatic water using sterile technique, following the same principles covered in our general reconstitution guide. Lyophilized material is generally stored cool and protected from light, and reconstituted solutions are typically refrigerated and used within the window validated by the laboratory's own storage protocol.

As with any research peptide, the quality of the material determines the quality of the resulting data. A batch-specific certificate of analysis documenting HPLC purity and mass-spectrometry identity is the standard way to verify that a given lot is both what it claims to be and free of significant synthesis impurities. Optimum ReGen Peptides supplies SS-31 for laboratory research with third-party batch testing and a published COA, compounded in the United States by a licensed 503A pharmacy. Researchers should always verify the COA for the specific lot they receive before beginning work.