Quick answer
SS-31 (elamipretide) is a mitochondria-targeted peptide that binds cardiolipin, a lipid in the inner mitochondrial membrane, to stabilize its structure, improve electron transport chain efficiency, reduce reactive oxygen species, and support ATP synthesis. It is an investigational drug studied across mitochondrial, cardiac, kidney, and neurological conditions, with mixed clinical results — not an approved medicine or supplement.
Key takeaways
- SS-31 (elamipretide) concentrates inside mitochondria, unlike broadly-acting antioxidants.
- It works by binding and stabilizing cardiolipin in the inner mitochondrial membrane.
- This is thought to preserve membrane structure, improve ATP synthesis, and lower ROS.
- It has been studied in mitochondrial diseases, cardiovascular, kidney, and neurodegenerative conditions, with mixed trial results.
- It is an investigational drug — not an approved medicine or dietary supplement.
What SS-31 is
SS-31 — also known as elamipretide (and by research names MTP-131 and Bendavia) — is a small, mitochondria-targeted peptide belonging to the Szeto-Schiller class. Unlike most antioxidants, which diffuse broadly, SS-31 concentrates inside the mitochondria, where the action is.
Critical context: SS-31 / elamipretide is an investigational drug — it has been studied in clinical trials but is not an approved medicine or dietary supplement. This article is educational only and provides no dosing or sourcing.
The mechanism: protecting cardiolipin
SS-31’s defining feature is that it selectively binds cardiolipin, a signature lipid of the inner mitochondrial membrane. Cardiolipin is essential for organizing the electron transport chain and maintaining the membrane’s structure — and it is vulnerable to oxidative damage. By binding and stabilizing cardiolipin, SS-31 is thought to:
- preserve the structure of the inner membrane and its cristae,
- improve the efficiency of the electron transport chain,
- reduce reactive oxygen species (ROS) production, and
- support ATP synthesis.
In other words, rather than mopping up free radicals after the fact, SS-31 aims to keep the energy-producing machinery structurally intact so it leaks less and works better.
What it’s been studied for
Because so many conditions involve mitochondrial dysfunction, SS-31/elamipretide has been investigated across a wide range of areas in trials and preclinical work:
- Primary mitochondrial diseases — including genetic conditions like Barth syndrome, where mitochondrial energy production is impaired.
- Cardiovascular — protecting heart tissue during reduced blood flow and supporting cardiac energetics.
- Kidney — acute and chronic kidney injury.
- Neurodegeneration — Alzheimer’s and Parkinson’s models.
- Age-related muscle decline — improving energy production and exercise tolerance in aged animal models.
Clinical trial results across these indications have been mixed — some encouraging signals, some trials that did not meet their primary endpoints — which is precisely why it remains investigational rather than approved.
How SS-31 differs from the other mitochondrial peptides
SS-31 is mechanistically distinct from MOTS-c and Humanin. Those are mitochondrial-derived signaling peptides encoded by the mitochondrial genome. SS-31 is a synthetic, mitochondria-targeted compound that acts physically on the inner membrane. Different origin, different mechanism — united by the mitochondrion as the target.
The honest status
SS-31/elamipretide has one of the most elegant and specific mechanisms in mitochondrial medicine, but it is an investigational drug with mixed clinical results and no approval as a supplement or medicine. We present the science for education only. See our Medical Disclaimer.
Frequently asked questions
How does SS-31 work?
It selectively binds cardiolipin, a signature lipid of the inner mitochondrial membrane that organizes the electron transport chain. By stabilizing cardiolipin, SS-31 aims to preserve membrane structure, improve energy-production efficiency, reduce reactive oxygen species, and support ATP synthesis — protecting the machinery rather than just neutralizing free radicals afterward.
Is SS-31 / elamipretide approved?
No. It is an investigational drug that has been studied in clinical trials but is not an approved medicine or dietary supplement. Trial results across conditions have been mixed, which is why it remains investigational. This article is educational only.
How is SS-31 different from MOTS-c and Humanin?
MOTS-c and Humanin are mitochondrial-derived signaling peptides encoded by the mitochondrial genome. SS-31 is a synthetic, mitochondria-targeted compound that acts physically on the inner membrane by binding cardiolipin. Different origins and mechanisms, same organelle as the target.
What has SS-31 been studied for?
Primary mitochondrial diseases (including Barth syndrome), cardiovascular protection, kidney injury, neurodegeneration, and age-related muscle decline. Evidence ranges from preclinical models to clinical trials with mixed outcomes. These are research contexts, not established treatments.
References
- 1.Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. Br J Pharmacol. 2014;171(8):2029-2050.
- 2.Birk AV, et al. The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin. J Am Soc Nephrol. 2013;24(8):1250-1261.
- 3.Karaa A, et al. Randomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy (MMPOWER). Neurology. 2018;90(14):e1212-e1221.
- 4.Chatfield KC, et al. Elamipretide improves mitochondrial function in Barth syndrome. (clinical research on cardiolipin-related disease).