SS-31

SS-31 is the common research designation for Elamipretide, also documented in the peptide science literature as Szeto-Schiller peptide 31, Bendavia, or MTP-131. Structurally it is a small aromatic-cationic tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2, built from alternating positively charged and aromatic residues. That alternating sequence is the design feature researchers point to when explaining why SS-31 behaves differently from most peptides studied in cell biology: instead of acting at a surface receptor, it partitions directly into the inner mitochondrial membrane, which is the structural basis for calling it a mitochondrial-targeted peptide.

In laboratory research, SS-31 is studied primarily for its interaction with cardiolipin, a phospholipid found almost exclusively in the inner mitochondrial membrane and required for organizing the electron transport chain into functional supercomplexes. Investigators use SS-31 as a chemical probe to ask what changes when cardiolipin architecture is preserved under stress, tracking readouts such as membrane potential, cristae morphology by electron microscopy, and electron transport chain complex activity in isolated mitochondria and cultured cell models.

The Szeto-Schiller peptide series, named for the chemists who first characterized this class of aromatic-cationic peptides, was developed specifically to concentrate in mitochondria without relying on a delivery vehicle or targeting sequence. SS-31 is the most widely cited compound from that series in the published research record, and it is frequently referenced alongside related probes when researchers are mapping structure-activity relationships for mitochondrial-membrane-directed peptides.

A large share of the preclinical literature on SS-31, referred to as Elamipretide in that body of work, concerns oxidative stress and bioenergetic dysfunction models: ischemia-reperfusion protocols in isolated heart and kidney tissue, aged-cell and senescence models, and genetic cardiolipin-deficiency models such as Barth syndrome cell lines. Researchers in these settings typically quantify reactive oxygen species output with probes like MitoSOX or DCF-DA, and pair that with ATP production assays and oxygen consumption measurements to characterize mitochondrial respiratory function.

Because SS-31 and Elamipretide describe the same molecule, literature search strategies for this compound need to track both terms, along with Szeto-Schiller peptide 31 and MTP-131, to capture the full relevant dataset. This naming overlap is a frequent point of confusion for researchers building a bibliography, since older biochemistry papers tend to use the Szeto-Schiller or SS-31 designation while later publications adopt the Elamipretide name.

Optimum ReGen Peptides supplies SS-31 as a lyophilized research compound intended strictly for in vitro and preclinical laboratory use, not for human or animal administration. Each batch is compounded by a licensed US pharmacy and verified through independent third-party testing for identity and purity before it is made available to buy for research. Proper laboratory handling, aseptic reconstitution technique, and storage at the recommended temperature are the responsibility of the purchasing laboratory.

SS-31 (Elamipretide) is in stock and available to buy online from Optimum ReGen Peptides — a real American research-peptide company with a physical storefront in Medford, Oregon, not an anonymous overseas dropshipper. Priced from $60, every order ships within two business days, flat $13 nationwide, in plain discreet packaging with tracking.

As your SS-31 supplier we back every batch with a third-party certificate of analysis and compound in a licensed US 503A pharmacy. Vials are supplied lyophilized at analytical purity for laboratory and research use only, not for human consumption.

In laboratory research, SS-31 is applied to isolated mitochondria preparations, cell cultures, or living cells to examine its effects on mitochondrial membrane potential (assessed by JC-1 or TMRE fluorescence), oxygen consumption rate (measured by Seahorse XF analysis), and ROS generation (measured by MitoSOX or analogous fluorescent probes).

Preclinical in vivo studies administer SS-31 to rodents before or after ischemic insults, measuring cardiac function by echocardiography and pressure-volume loop analysis, renal function by creatinine and BUN levels, and tissue histology to assess the extent of injury and any protective effects associated with treatment.

Biochemical studies use blue native PAGE and electron microscopy to examine ETC complex superassembly and cristae ultrastructure in mitochondria treated with SS-31, providing structural correlates for observed functional improvements in bioenergetics assays. Cardiolipin content and acyl chain composition are measured by mass spectrometry to characterize the lipid environment of the IMM.