Epitalon
Epithalon · pineal tetrapeptide
Synthetic pineal tetrapeptide. Not FDA-approved; evidence is largely preclinical.
Also known as · Elamipretide · Bendavia
SS-31
Mitochondria-targeting peptide. FDA-approved (elamipretide) only for Barth syndrome.
What it is
SS-31 (also called elamipretide or Bendavia) is a small synthetic peptide designed to target the mitochondrial inner membrane. It was developed by Stealth BioTherapeutics for investigation in mitochondrial dysfunction-related conditions.
The peptide has been studied in clinical trials for several rare mitochondrial diseases, ischemic injury, and certain cardiovascular conditions. It has received regulatory designations including Orphan Drug status for some indications. In 2025, the FDA granted accelerated approval to elamipretide (brand name Forzinity) for Barth syndrome only; it is not FDA-approved for any other use in the United States.
Mechanism of action
Proposed mechanisms come from laboratory and animal research. In these models, SS-31 has been reported to concentrate at the mitochondrial inner membrane, where it:
- Binds cardiolipin: has been reported to bind cardiolipin, an inner membrane phospholipid involved in electron transport chain function
- Affects mitochondrial respiration: was associated with changes in ATP production measures in laboratory studies
- Affects oxidative stress markers: was associated with lower mitochondrial reactive oxygen species in cell and animal models
- Cell permeability: the peptide structure has been reported to cross cell membranes without receptor-mediated uptake
Clinical evidence
SS-31 has been evaluated in clinical trials for:
- Mitochondrial myopathies (Barth syndrome, primary mitochondrial myopathy)
- Heart failure with preserved ejection fraction
- Ischemia-reperfusion injury
- Age-related macular degeneration
- Renal injury
Results have been mixed. Several larger studies did not meet their primary endpoints. Well-controlled human trials establishing effectiveness and safety for most of these uses are lacking.
Why we don’t prescribe it at The Tide
The Tide does not prescribe SS-31. It remains an investigational compound without an established clinical pathway for routine use. Anyone with concerns about mitochondrial or metabolic health should discuss them with a licensed healthcare provider.
Side effects and contraindications
Human safety has not been established outside of clinical trial settings, and long-term effects are unknown. Injection site reactions and gastrointestinal effects were reported in trials. Products sold outside regulated channels (e.g., “research peptides”) may vary in purity, dose, and sterility.