Research use only. The materials discussed on this page are sold exclusively for in vitro laboratory research. They are not for human or veterinary use, and nothing here is medical advice or a claim of benefit. Animal-model and clinical data are mentioned only as cited published literature.
MOTS-c and SS-31 (Elamipretide) are two peptides studied for their action on mitochondrial function, but they work via completely different mechanisms. MOTS-c is a signaling mitochondrial-derived peptide (MDP), while SS-31 specifically targets cardiolipin in the inner mitochondrial membrane. This comparison is intended for bioenergetics and longevity researchers.
The two compounds
Comparison table
| Property | MOTS-c | SS-31 |
|---|---|---|
| Class | MDP (Mitochondrial-Derived Peptide) — signaling | Cardiolipin-targeting peptide — membrane protection |
| Origin | Mitochondrial 12S rRNA (encoded by mtDNA) | Synthetic peptide (D-Arg-Dmt-Lys-Phe-NH2) — Stealth BioTherapeutics |
| Molecular target | AMPK, cellular metabolic pathways | Cardiolipin in inner mitochondrial membrane |
| Mitochondrial effect | Activates mitochondrial biogenesis via AMPK/PGC-1α | Stabilizes cardiolipin, optimizes respiratory chain |
| Structure | 16 amino acids (naturally encoded peptide) | Synthetic cationic D-enantiomer tetrapeptide |
| Half-life | Short (~30 min) | Moderate (~2 h) |
| Research applications | Metabolic aging, insulin resistance, sarcopenia | Mitochondrial cardiomyopathy, ischemia/reperfusion, neuroprotection |
| Clinical stage (info) | Primarily preclinical research | Clinical-stage compound (elamipretide); verify current regulatory status against FDA records |
| Purity documentation | Batch CoA (HPLC) | Batch CoA (HPLC) |
Research contexts
Literature contexts for MOTS-c
Metabolic aging studies, insulin resistance models, research on mitochondrial biogenesis and AMPK, sarcopenia.
Literature contexts for SS-31
Cardiology studies (ischemia/reperfusion), neuroprotection, primary mitochondrial disease models, respiratory chain optimization.
Mechanisms of action
MOTS-c
MOTS-c is a peptide encoded in mitochondrial 12S ribosomal RNA. Once translated, it is reported in cell-culture and rodent literature to act as a systemic metabolic signal through the AMPK pathway, with associated changes in insulin signaling, fatty acid β-oxidation and mitochondrial biogenesis via PGC-1α. Discovered in 2015 (Lee et al., Cell Metabolism).
SS-31
SS-31 (D-Arg-Dmt-Lys-Phe-NH2) is a cationic tetrapeptide that selectively accumulates in the inner mitochondrial membrane via electrostatic interaction with cardiolipin, a phospholipid unique to this membrane. It stabilizes respiratory chain supercomplexes and optimizes ATP production.
Combined research context
Both peptides are studied in aging and mitochondrial dysfunction models, but their mechanisms are complementary: MOTS-c acts as a systemic metabolic signal (AMPK), while SS-31 locally protects the respiratory chain machinery (cardiolipin). The research-grade materials discussed here are for laboratory use only.
Related research products
Axion Research Peptides supplies research-grade peptides for in vitro use, with a batch certificate of analysis. Browse MOTS-c, SS-31 or the full research catalog.
Frequently asked questions
Is MOTS-c a natural peptide?
Yes — MOTS-c is encoded in mitochondrial 12S ribosomal RNA and naturally expressed. It’s the first functionally characterized mitochondrial-derived peptide (MDP), discovered in 2015.
Why does SS-31 specifically target the mitochondrion?
Its sequence (D-Arg-Dmt-Lys-Phe-NH2) is cationic aromatic: it crosses the plasma membrane without a transporter then accumulates in the inner mitochondrial membrane via cardiolipin interaction (negatively charged phospholipid).
Which has more clinical data?
SS-31 (elamipretide, Stealth BioTherapeutics) has been the subject of clinical development programs, including for Barth syndrome; its current regulatory status should be verified against FDA records. MOTS-c remains primarily preclinical as of 2026.
Can they be studied in combination?
Theoretically yes — their mechanisms are non-overlapping. However, few combinatorial studies have been published. Any combination remains at the researcher’s discretion in their experimental protocol.
Are these peptides approved in the USA?
MOTS-c is not approved by the FDA, EMA, or MHRA. Elamipretide has a separate regulatory history as a clinical drug candidate (verify current status). The MOTS-c and SS-31 research materials offered by Axion Research Peptides are sold exclusively for in vitro scientific research.
Scientific references
- Lee C et al., 2015 — MOTS-c discovery, Cell Metabolism.
- Szeto HH, 2014 — SS peptides cardiolipin, Br J Pharmacol.
Regulatory disclaimer
The peptides discussed in this comparison are not approved by the FDA, EMA, MHRA, or any regulatory agency for human or veterinary clinical use, except where a specific approved product is named (for example, tesamorelin as Egrifta). They are sold by Axion Research Peptides exclusively for in vitro scientific research. This page summarizes published literature and is neither medical advice nor a recommendation for clinical use.
