SS-31 (Elamipretide): The Mitochondria-Targeting Peptide

What SS-31 is

SS-31 is a Szeto-Schiller tetrapeptide (hence the "SS"), cell-permeable and mitochondria-targeting. Its sequence is D-Arg-2',6'-dimethylTyr-Lys-Phe-NH₂. Under the clinical name elamipretide it has been developed by Stealth BioTherapeutics and evaluated in clinical trials.

It is an investigational compound — it remains in Phase 2/3 trials and is not approved by the FDA or any regulatory agency for human use. What distinguishes SS-31 from other antioxidants is that it does not act diffusely across the body: it selectively accumulates where it matters most, inside the mitochondrion itself.

Cardiolipin and the inner mitochondrial membrane

The mitochondrion has two membranes. The inner membrane folds into structures called cristae, and that is where the electron-transport chain that makes energy lives. A unique phospholipid, cardiolipin, is abundant in this inner membrane and acts as the "scaffold" that keeps the folds compact and organizes the respiratory complexes.

SS-31 is a charged molecule that concentrates in the inner mitochondrial membrane and selectively binds cardiolipin. That binding does two key things:

• Stabilizes cristae structure — it keeps the folds well-formed instead of letting them collapse, as happens in damaged or aged mitochondria.
• Promotes supercomplex assembly — cardiolipin helps the electron-transport-chain complexes cluster into efficient "supercomplexes"; by protecting it, SS-31 helps preserve that organization.

In other words, SS-31 does not add energy: it protects the physical architecture that lets the mitochondrion produce energy well.

Function: ATP, cristae, and ROS control

The consequences of stabilizing cardiolipin translate into three researched effects:

• Improved electron-transport-chain efficiency — with cristae and supercomplexes preserved, electrons flow with fewer "leaks."
• Restored ATP production — a more efficient transport chain recovers the synthesis of the cell's main fuel.
• Reduced excess reactive oxygen species (ROS) — when the chain leaks electrons it generates free radicals; by sealing those leaks, SS-31 lowers oxidative stress at its source rather than neutralizing it afterward.

This logic — repair the source instead of mopping up the damage — is what sets SS-31 apart from classic antioxidants.

Research areas

SS-31 / elamipretide has been studied in conditions where mitochondrial dysfunction is central:

• Heart failure — the heart is the organ with the highest mitochondrial density; maintaining bioenergetics is of direct interest.
• Primary mitochondrial myopathies — rare genetic diseases where the mitochondrion fails; one of the most studied areas in clinical trials.
• Ischemia-reperfusion injury — the damage that appears when blood flow returns to a tissue deprived of oxygen.
• Age-related mitochondrial decline — progressive loss of mitochondrial function is a hallmark of cellular aging.
• Eye / retinal conditions — the retina is highly dependent on mitochondrial energy.

All of these remain investigational uses: the data come from Phase 2/3 studies and preclinical models, not from an approved product.

SS-31 vs MOTS-c

Both peptides are associated with mitochondrial health, but they act through completely different routes. One is structural; the other is a signaling molecule.

Peptide	Type of action	Core idea
SS-31	Structural	Binds cardiolipin and stabilizes the inner membrane / cristae
MOTS-c	Signaling	Mitochondrial-genome-derived peptide that regulates metabolism (AMPK)

SS-31 protects the mitochondrion's "physical machinery"; MOTS-c acts as a messenger that tunes how the cell uses energy. They are not interchangeable, which is why they are considered complementary in research. We go deeper on the latter in our MOTS-c: The Mitochondrial Metabolism Peptide guide.

Reconstitution

The SS-31 10 mg vial comes as lyophilized powder and is reconstituted with bacteriostatic water at the concentration you define.

Calculation example (10 mg vial + 2 mL bacteriostatic water = 5 mg/mL): to research 5 mg → 1 mL → 100 units on a U100 syringe. If you reconstitute with 1 mL you get 10 mg/mL, and half the volume would deliver the same dose.

Refrigerate (2–8 °C) after reconstitution and protect from light. For custom calculations use the reconstitution calculator or see the complete reconstitution guide.

SS-31 at Renova

SS-31 is available as a 10 mg vial at $135, lyophilized powder.

Our material is manufactured in a cGMP-compliant US lab that we work with directly, with a Certificate of Analysis (COA) by HPLC and mass spectrometry.