SS-31 (Elamipretide): The Good, The Bad & The Research
SS-31 (Elamipretide) concentrates 5,000-fold at the inner mitochondrial membrane. Research on cardiolipin protection, ATP restoration, cardiac function and Phase II clinical trials.
Jun 16, 2026 | 8 Minute Read
What Is SS-31?
SS-31 is a synthetic mitochondria-targeting tetrapeptide developed by researchers Hazel H. Szeto and Peter W. Schiller — hence the name Szeto-Schiller 31. It is also known by the names Elamipretide, MTP-131, and Bendavia in clinical research settings.
SS-31 is a small, water-soluble peptide composed of four amino acids: D-Arg-Dmt-Lys-Phe-NH2. Its unique alternating aromatic-cationic structure gives it a remarkable ability to pass through cell membranes and concentrate specifically at the inner mitochondrial membrane — at levels up to 5,000 times greater than surrounding tissue.
This targeted concentration is what makes SS-31 one of the most studied mitochondria-specific compounds in preclinical research. Rather than acting broadly throughout the body, SS-31 goes directly to the source of the problem: the mitochondria.
CAS Number: 736992-21-5
Molecular Formula: C32H49N9O5
Molecular Weight: 639.79 g/mol
⚠️ SS-31 is not FDA approved for human use. All research discussed is preclinical or early-stage clinical. For Research Use Only.
How Does SS-31 Work? (Mechanism of Action)
To understand SS-31, you need to understand one molecule: cardiolipin.
Cardiolipin is a specialized phospholipid found almost exclusively in the inner mitochondrial membrane. It plays a critical role in maintaining the structure of the respiratory chain — the series of protein complexes that generate ATP (cellular energy). When cardiolipin becomes damaged or oxidized, the entire energy production process deteriorates. Mitochondria fragment, ATP output drops, reactive oxygen species (ROS) accumulate, and cells begin to dysfunction.
