What is SS-31 (Elamipretide)?
SS-31, also known as elamipretide, is a mitochondria-targeted tetrapeptide studied for its unusual mechanism: rather than acting on a cell-surface receptor, it selectively binds cardiolipin — a phospholipid found almost exclusively in the inner mitochondrial membrane. This gives SS-31 a distinct research profile among longevity compounds, positioning it as a tool for studying mitochondrial membrane structure and bioenergetics directly, rather than upstream metabolic signaling.
What SS-31 Is
SS-31 is a synthetic tetrapeptide with an alternating aromatic-cationic amino acid sequence, developed specifically to concentrate at the inner mitochondrial membrane. Unlike most peptides, which distribute broadly through extracellular and cytoplasmic compartments, SS-31's structure gives it a strong electrostatic affinity for cardiolipin — a phospholipid that is essentially unique to the inner mitochondrial membrane and central to how that membrane folds into its characteristic cristae structure.
Mechanism of Action: Cardiolipin Binding
Cardiolipin is required for the proper folding of the inner mitochondrial membrane into cristae, and it plays a structural role in organizing the protein complexes of the electron transport chain. When cardiolipin becomes oxidized or mislocalized — a change associated with aging and mitochondrial dysfunction — cristae structure and electron transport efficiency can be compromised, and reactive oxygen species (ROS) production can increase.
SS-31's binding to cardiolipin is studied for its ability to help preserve normal cristae architecture and support efficient electron transport chain function under these conditions, with a downstream effect of reduced excess ROS production. Because this mechanism acts directly at the membrane rather than through a signaling cascade, SS-31 is often described in research literature as a "structural" mitochondrial protectant rather than a metabolic modulator.
SS-31 vs NAD+: Two Different Layers of Mitochondrial Research
SS-31 and NAD+ are both frequently referenced in longevity and mitochondrial research, but they act at entirely different layers of mitochondrial biology:
| Parameter | SS-31 (Elamipretide) | NAD+ |
|---|---|---|
| Site of action | Inner mitochondrial membrane (cardiolipin) | Coenzyme pool throughout metabolism & sirtuin pathways |
| Mechanism type | Structural — direct membrane binding | Metabolic — coenzyme substrate for redox reactions and sirtuins |
| Primary research angle | Membrane integrity, ROS reduction, cristae architecture | Cellular energy metabolism, DNA repair, sirtuin-mediated gene regulation |
| Research models | Cardiac and skeletal muscle mitochondrial aging | Broad cellular aging, metabolic and epigenetic research |
Because the two compounds act on different layers of mitochondrial biology — one structural, one metabolic — they are frequently studied as complementary rather than competing research tools. See our What is NAD+ guide for a full breakdown of the coenzyme pathway side of mitochondrial research.
Research Applications
SS-31 is most frequently referenced in research investigating mitochondrial bioenergetics, reactive oxygen species regulation, and cardiolipin-membrane interactions. It is a common reference compound in cardiac and skeletal muscle aging research models exploring mitochondrial membrane stability and oxidative stress pathways, where structural mitochondrial dysfunction is a central variable under study.
Reconstitution for Research
SS-31 is supplied as a lyophilized (freeze-dried) powder and must be reconstituted with Bacteriostatic Water before use in research protocols.
Standard protocol for the 10mg vial: Add 2 mL Bacteriostatic Water for a concentration of 5 mg/mL. Inject the BAC Water slowly down the vial wall and swirl gently — do not shake. The solution should be clear and colorless. Refrigerate at 2–8°C after reconstitution. Stable 28–42 days.
For full reconstitution parameters and a dosing calculator that computes exact draw volumes, visit our Reconstitution Guide and Dosing Calculator.