ss-31

SS-31 selectively binds to cardiolipin in the inner mitochondrial membrane, stabilizing its structure and promoting functional mitochondrial cristae formation. This optimizes the electron transport chain (ETC) by enhancing the interaction between respiratory complexes (I, III, IV) and ATP synthase, thereby increasing ATP production and reducing electron leakage. Consequently, it decreases reactive oxygen species (ROS) generation and oxidative stress. Additionally, SS-31 inhibits the opening of the mitochondrial permeability transition pore (mPTP), preventing cytochrome c release and apoptosis activation. It also modulates mitochondrial dynamics, favoring fusion over fission, and reduces inflammation by inhibiting NLRP3 inflammasome activation.

• Cardiolipin stabilization: Binds to cardiolipin, maintaining inner mitochondrial membrane integrity.
• ETC optimization: Improves respiratory complex coupling, enhancing energy efficiency.
• ROS reduction: Decreases free radical production and oxidative damage.
• mPTP inhibition: Prevents permeability transition pore opening, reducing apoptosis.
• Mitochondrial dynamics modulation: Promotes mitochondrial fusion and improves mitochondrial network.
• Anti-inflammatory effect: Inhibits NLRP3 inflammasome activation and reduces pro-inflammatory cytokines.

• Heart failure: Improves mitochondrial function in cardiomyocytes, enhancing contractility and reducing ischemic damage.
• Chronic kidney disease: Protects renal tubular cell mitochondria, decreasing fibrosis and loss of kidney function.
• Parkinson's disease: Protects dopaminergic neurons from oxidative stress and mitochondrial dysfunction.
• Age-related macular degeneration: Preserves retinal pigment epithelial cell function by reducing oxidative damage.
• Mitochondrial myopathies: Improves ATP production and reduces symptoms in patients with mitochondrial mutations.
• Anti-aging: Counteracts age-related mitochondrial decline, improving cellular health and longevity.

SS-31 produces an increase in cellular ATP production, improved energy efficiency, and reduced oxidative stress. Observed effects include improved cardiac function (ejection fraction), increased exercise capacity, reduced fatigue, improved renal function (decreased proteinuria), neuroprotection with improved motor function in Parkinson's models, and vision preservation in macular degeneration. Decreased inflammatory and apoptotic markers have also been reported. Effects are most notable in tissues with high energy demand such as heart, kidney, brain, and retina.

SS-31 is generally well tolerated in clinical studies. The most common adverse effects include injection site reactions (pain, redness), mild nausea, and headache. No serious toxicities have been reported. It is contraindicated in patients with known hypersensitivity to the peptide or any of its excipients. Use during pregnancy or lactation is not recommended due to lack of safety data. It may interact with other drugs affecting mitochondrial function, such as some antiretrovirals or statins, although no clinically significant interactions have been documented. Caution is advised in patients with severe hepatic or renal impairment, as pharmacokinetics have not been studied in these populations. As an investigational peptide, its use should be under medical supervision and within clinical trials or expanded access programs.

SS-31 (Elamipretide) is not approved by the FDA, EMA, or any other regulatory agency for general clinical use. It is in clinical research (phase 2 and 3 trials) for indications such as heart failure with preserved ejection fraction (HFpEF), chronic kidney disease, age-related macular degeneration, and Leigh syndrome. It has received orphan drug designation from the FDA for the treatment of primary mitochondrial myopathy and Barth syndrome. Its development is led by Stealth BioTherapeutics.

Typical doses in clinical trials vary by indication. For heart failure, intravenous administration of 0.5 mg/kg/day for 5 days has been used. For chronic kidney disease, 40 mg/day subcutaneously for 12 weeks. For macular degeneration, 40 mg/day subcutaneously for 24 weeks. No standard dose is established outside of research.

Lyophilized SS-31 should be stored at -20°C, protected from light and moisture. Once reconstituted with sterile water or saline, it should be used immediately or stored at 2-8°C for no more than 24 hours. Do not freeze after reconstitution. Avoid repeated freeze-thaw cycles.