SS-31 Elamipretide: Mitochondrial-Targeted Peptide Research 2026

What is SS-31?

SS-31 (also called Elamipretide or Szeto-Schiller 31) is a mitochondria-targeted tetrapeptide with sequence D-Arg-2′,6′-Dmt-Lys-Phe-NH2 and a molecular weight of 638.8 Da. The compound is a research tool for investigating mitochondrial inner-membrane biology — selectively partitioning to the inner mitochondrial membrane via electrostatic interaction with cardiolipin, a phospholipid uniquely abundant on the inner mitochondrial membrane. The D-amino acid configuration provides protease resistance supporting research-tool stability. Researchers can access SS-31 research peptide at Advanced Peptide Science.

Research Background: Mitochondrial Targeting via Cardiolipin

SS-31 was developed by Szeto and Schiller as part of a programme designing cell-permeable peptides that selectively concentrate at the inner mitochondrial membrane. The targeting mechanism exploits the unique membrane composition of mitochondria: cardiolipin is a phospholipid found almost exclusively on the inner mitochondrial membrane, where it contributes ~20% of total phospholipid content. SS-31’s alternating cationic and aromatic residue pattern enables electrostatic and hydrophobic interaction with cardiolipin — concentrating the peptide at the inner membrane where electron transport chain complexes reside.

Mechanism of Action

Mechanism research investigates SS-31 association with cardiolipin on the inner mitochondrial membrane. Downstream effects under investigation include stabilisation of cristae structure (the highly folded inner-membrane topology supporting electron transport chain function), improved electron transport chain Complex I-IV coupling efficiency, reduced reactive oxygen species (ROS) production from electron transport chain leakage, and modulation of mitophagy (selective autophagy of damaged mitochondria) pathway dynamics. The compound thus provides a research-tool framework for investigating inner-membrane structure-function relationships in mitochondrial biology.

Key Research Findings

Cardiolipin Binding and Inner-Membrane Stabilisation

Cardiolipin is essential for proper assembly and function of the electron transport chain complexes. SS-31 research investigates how peptide binding to cardiolipin affects cristae structure maintenance, electron transport chain complex assembly, and downstream bioenergetic capacity. The mechanism is mechanistically distinct from compounds acting on mitochondrial gene expression or biogenesis pathways.

Electron Transport Chain Coupling Efficiency

Electron transport chain “coupling” refers to the efficiency with which electron flow drives proton pumping and ATP synthesis vs leaks contributing to ROS generation. SS-31 research investigates whether peptide-stabilised cardiolipin organisation improves coupling efficiency, with downstream effects on ATP synthesis rates and ROS production.

Mitophagy Modulation

Mitophagy is the selective autophagy of damaged mitochondria, removing dysfunctional organelles before they contribute to oxidative damage or apoptotic signalling. SS-31 research investigates effects on mitophagy pathway dynamics — whether the compound supports or modulates the selective clearance machinery.

Research Applications and Comparison

SS-31 occupies a distinctive position in the Longevity & Immune Support category as the only mitochondrial-membrane-targeting research peptide in the catalogue. Comparative research with the mitochondrial-derived peptides MOTS-c (12S rRNA-encoded, AMPK-pathway) and Humanin (16S rRNA-encoded, BAX-pathway) provides comprehensive mitochondrial biology research framework spanning gene-expression-derived peptides and direct membrane-targeting compounds. Additional category compounds for ageing research include Epitalon (telomerase research), FOXO4-DRI (senolytic), and Thymosin Alpha-1 (immune modulation).

Research Specifications

Molecular Weight	638.8 Da
Sequence	D-Arg-2′,6′-Dmt-Lys-Phe-NH2 (D-amino acid tetrapeptide)
Targeting Mechanism	Selective inner-mitochondrial-membrane partitioning via cardiolipin binding
Primary Research Focus	Electron transport chain, cristae structure, mitochondrial bioenergetics
Format	Lyophilized powder in sterile vial
Purity	≥ 99% (HPLC verified)
Storage	-20 °C, protect from light

Frequently Asked Questions

What does SS-31 stand for?

SS-31 stands for Szeto-Schiller 31 — referring to the research group (Szeto and Schiller) that developed the compound and the 31st iteration in their mitochondrial-targeted peptide series. The compound is also called Elamipretide.

Why does SS-31 target mitochondria?

The compound’s alternating cationic and aromatic residue pattern enables electrostatic and hydrophobic interaction with cardiolipin — a phospholipid uniquely abundant on the inner mitochondrial membrane. This targeting concentrates SS-31 at its site of action.

How does SS-31 differ from mitochondrial-derived peptides?

SS-31 is a synthetic compound that targets the mitochondrion from outside. MOTS-c and Humanin are endogenously encoded within mitochondrial DNA (rRNA genes) — they originate inside the mitochondrion and may signal outward.

Is SS-31 approved for human use?

Advanced Peptide Science supplies SS-31 exclusively for in vitro and in vivo scientific research. Not for human consumption. Research use only.

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For Research Use Only. Not for human consumption. Not intended to diagnose, treat, cure, or prevent any disease.