SS-31

Mitochondrial-targeted peptide · Also known as Elamipretide, Bendavia, MTP-131

What is SS-31?

A cell-permeable tetrapeptide that concentrates in the inner mitochondrial membrane, stabilizing cardiolipin and restoring efficient energy production. In clinical trials for heart failure and mitochondrial diseases.

SS-31 (elamipretide) is a synthetic tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) that crosses cell membranes and localizes to the inner mitochondrial membrane. It binds to cardiolipin, a phospholipid essential for electron transport chain function, protecting it from oxidative damage and restoring mitochondrial efficiency.

Key takeaway: SS-31 is the most clinically advanced mitochondrial peptide, with Phase 2/3 trials showing improvements in heart failure and Barth syndrome. It targets the root cause of age-related mitochondrial decline.

Benefits & evidence

Mitochondrial function High confidence
Cardiac function Moderate confidence
Exercise capacity Moderate confidence
Cellular energy Moderate confidence
Longevity Preliminary confidence

How it works

Mitochondrial dysfunction is a hallmark of aging. As we age, cardiolipin (a lipid unique to the inner mitochondrial membrane) becomes oxidized, disrupting the electron transport chain and increasing ROS production in a vicious cycle.

SS-31 binds selectively to cardiolipin, stabilizing its structure and the arrangement of respiratory chain complexes. This restores efficient ATP production and reduces electron leak that generates harmful ROS.

In clinical trials, SS-31 improved six-minute walk distance in heart failure patients and reduced hospitalizations. In Barth syndrome (a genetic cardiolipin deficiency), it showed meaningful functional improvements.

Dosing information

Typical dosing protocol
Starting dose

0.25 mg/kg SC

Daily
Maintenance dose

0.25 mg/kg SC

Ongoing

Clinical trials use subcutaneous or IV administration. Research peptide dosing protocols are not standardized.

Side effects

Most side effects tend to improve as your body adjusts.

Injection site reactions Common
Headache Common
Dizziness Moderate

Research (10 studies)

2025 FDA TIDES (Peptides and Oligonucleotides) Harvest. Pharmaceuticals (Basel, Switzerland) · 2026
Energy-replenishing, mitochondria-targeted hydrogel microspheres mitigate sarcopenia via cellular senescence amelioration. Journal of controlled release : official journal of the Controlled Release Society · 2026
Targeted nanoliposomal nutrient delivery for human health. World journal of gastrointestinal pharmacology and therapeutics · 2025