Elamipretide (SS-31)

Elamipretide (SS-31) is a synthetic tetrapeptide composed of four amino acids: D-Arg-dimethylTyr-Lys-Phe-NH₂. It was developed from research on mitochondria-targeting peptides designed to protect and restore mitochondrial function by binding to cardiolipin in the inner mitochondrial membrane.

Elamipretide is purported to improve cellular energy production, enhance mitochondrial efficiency, and reduce oxidative stress. Research suggests it may support heart, muscle, and eye health by improving mitochondrial bioenergetics and reducing damage from reactive oxygen species.

Research in animal and cellular models indicates that Elamipretide (SS-31) improves mitochondrial energy production by increasing ATP generation and enhancing adenosine diphosphate (ADP) sensitivity. For example, in aging mouse muscle SS-31 treatment restored ATPmax, improved the P/O ratio and increased treadmill endurance without raising mitochondrial content. Studies in explanted human hearts found improved electron transport coupling after SS-31 exposure ^{1, 2}.

Additionally, SS-31 has been found to reduce oxidative stress and preserve cellular structure across diverse tissues. In a murine model of lipopolysaccharide-induced cognitive impairment SS-31 reduced mitochondrial reactive oxygen species, preserved synaptic proteins and improved performance on memory tests ³. In aging skeletal muscle the peptide lowered markers of oxidative damage and reversed cysteine S-glutathionylation, pointing toward improved mitochondrial quality and reduced cellular stress ⁴. Overall, the main benefits of SS-31 include enhanced mitochondrial energy output and reduced oxidative stress with improved cellular and tissue performance.

In clinical studies, Elamipretide (SS-31) has been associated with headaches in approximately 16.7 % of participants in one dose-escalation trial. Dizziness was also reported in about 8.3 % of participants in that trial ⁵. Other less frequently reported effects include abdominal pain, flatulence, nausea and fatigue in trials and review articles. More broadly, reviews of the research note that while Elamipretide is generally well-tolerated, adverse events led to treatment discontinuation in some cases (for example 7.3 % in one study) despite no deaths or hospitalizations deemed treatment-related ⁶. In sum, the main negative side effects of Elamipretide are mild to moderate symptoms such as headache, dizziness, and digestive discomfort, with no major safety signals reported so far, but more research is needed.

Elamipretide (SS-31) primarily targets the mitochondria by binding to the phospholipid cardiolipin on the inner mitochondrial membrane, which helps stabilize mitochondrial cristae structure and maintain the integrity of the electron transport chain. It also enhances mitochondrial ADP sensitivity by interacting with the adenine nucleotide translocator (ANT) and improving ADP uptake into mitochondria, which boosts ATP production and reduces proton leak in aged muscle and heart tissue ^{7, 8}. Furthermore, it lowers reactive oxygen species (ROS) production, mitigates oxidative stress and inflammation, and supports synaptic and mitochondrial function in neuronal models, thereby improving functional connectivity and mitochondrial biogenesis ⁹. In short, Elamipretide works by stabilizing mitochondrial membranes, improving ADP/ATP transport and production, and reducing oxidative/inflammatory damage to improve mitochondrial efficiency.

Elamipretide has an Orphan Drug Designation from the U.S. Food & Drug Administration (FDA) for treatment of Barth syndrome. It has been in late‑stage clinical development for this ultra‑rare mitochondrial disease ^{10, 11}. In sport, the World Anti‑Doping Agency (WADA) Prohibited List includes a category S0: Non‑approved substances (i.e., pharmacological substances not approved by a governmental regulatory health authority for human therapeutic use) and states that such substances are prohibited at all times ¹².