MOTS-c vs SS-31: Research Comparison | Peptide Intel Hub

MOTS-c is a 16-amino-acid mitochondrial-derived peptide encoded within the 12S rRNA region of the mitochondrial genome. In research models it has been characterised as a signalling peptide that influences nuclear gene expression and metabolic homeostasis, particularly through AMPK-axis activation.

SS-31 (elamipretide) is a synthetic four-amino-acid peptide (D-Arg-2',6'-dimethylTyr-Lys-Phe-NH2) that localises selectively to the inner mitochondrial membrane and binds to cardiolipin. The cardiolipin interaction is the proposed mechanism for its mitochondrial-protective effects in published research.

MOTS-c does not act through a single canonical receptor in the conventional sense — its proposed mechanism centres on intracellular AMPK-axis activation and downstream effects on nuclear metabolic gene expression.

SS-31 does not act through a cell-surface receptor either; its proposed mechanism is the direct interaction with cardiolipin at the inner mitochondrial membrane, stabilising mitochondrial cristae structure and preserving electron-transport-chain function in research models.

MOTS-c is a 16-residue peptide with a short native half-life; research protocols typically use daily or sub-daily cadences with bacteriostatic-water reconstitution and refrigerated in-use storage.

SS-31 is a small tetrapeptide with sub-cellular targeting and a similarly short native half-life. Research cadences are typically daily; the small molecular size simplifies penetration in cell-culture models compared with larger peptides.

MOTS-c is widely used in metabolic, exercise-physiology, insulin-sensitivity and longevity research models. The AMPK-axis activation profile makes it a common comparator against other metabolic-axis research compounds.

SS-31 is the leading research compound for mitochondrial-membrane and cardiolipin-interaction studies. It is widely used in ischaemia-reperfusion, neurodegeneration and mitochondrial-dysfunction research models where preserving electron-transport-chain function is the experimental endpoint.

Both MOTS-c and SS-31 ship from Regena Peptides only after independent third-party verification — Janoshik Analytical is the default verifier, with orthogonal independent laboratories used when batch chemistry calls for confirmation by a second method. Minimum release specification is ≥99.0% HPLC main-peak purity with matching mass-spectrometry molecular weight and water content within the published specification for the compound.

Batch COAs for both compounds are published on the Regena Peptides lab reports page so a research-peptide buyer can audit the analytical detail before purchase. The /trust/how-to-read-a-coa reference walks through every field on a modern Regena Peptides COA.

Both compounds ship lyophilised under nitrogen. Hold the unopened vial at 2–8 °C; freeze at −20 °C for long-term storage. Reconstitution with bacteriostatic water (0.9% benzyl alcohol) supports a two-month (60-day) in-use stability window under refrigeration. SS-31 is particularly sensitive to repeat freeze-thaw cycling — aliquot before any freeze.

Aliquot before any freeze. The single most common cause of measurable potency loss in research peptides is repeat freeze-thaw cycling — both MOTS-c and SS-31 benefit from single-thaw aliquot workflows. Vortex gently, never shake aggressively, and keep reconstituted vials away from direct light. The /research/compound-storage-guide reference covers the per-compound stability windows in detail.

Researchers choose MOTS-c when the protocol targets metabolic, exercise-physiology or AMPK-axis signalling outcomes. Researchers choose SS-31 when the protocol targets the inner mitochondrial membrane directly — cardiolipin interaction, electron-transport-chain preservation, ischaemia-reperfusion models — and when a small-molecule pharmacokinetic profile is preferred over a longer signalling peptide.

For multi-compound comparator studies, the Regena Peptides consultations team will reserve matched-batch inventory of both MOTS-c and SS-31 against a project timeline so the experimental panel is sourced under a single analytical specification window.

Both MOTS-c and SS-31 are supplied strictly for in-vitro and preclinical research use. They are not medicines, are not approved for human consumption in Spain, the United Kingdom, the European Union or the United States, and are not dispensed against a prescription. The research-use declaration ships with every package alongside the independent third-party COA.

Comparison pages on the Regena Peptides site exist for laboratory-research reference. Nothing on this page constitutes a recommendation for human use of either compound.