MOTS-c vs SS-31: why would researchers study both?
Research context reviewed 5 October 2026Both names appear in mitochondrial research. They ask different questions. MOTS-c is a peptide encoded by mitochondrial DNA that researchers study as an energy-response signal. SS-31, also called elamipretide, is a designed peptide studied for how it binds the inner mitochondrial membrane. One concerns how the cell responds; the other concerns the membrane the energy-making machinery sits in.
If both questions are in scope, compare MOTS-c and SS-31 as separate materials. Neither replaces the other.
What has MOTS-c done in research?
In cell and mouse experiments, MOTS-c activated AMPK, a signal cells use when energy is under pressure; treated mice fed a high-fat diet showed better insulin sensitivity than controls. In a different study, exercise increased the body's own MOTS-c in human blood and muscle. That study also included separate mouse experiments; it did not give MOTS-c to the human volunteers.
What has SS-31 done in research?
In model-membrane and isolated-mitochondria experiments, SS-31 bound cardiolipin-containing membranes and changed the electrical charge at their surface. Isolated mitochondria then needed less energy to handle calcium stress. Those are membrane experiments, not the MOTS-c signalling studies.
Pharmaceutical elamipretide has also been tested in people. A small Barth syndrome trial missed its two primary endpoints in the randomised comparison. A later open-label follow-up reported greater walking distance and improved symptom scores. Neither phase tested PEPTALIAS material or the two peptides together.
MOTS-c or SS-31: which fits the research question?
| Research question | Material to compare |
|---|---|
| Mitochondrial signals and energy-response pathways | MOTS-c |
| Inner-membrane behaviour and cardiolipin | SS-31 |
| Both mechanisms, studied with separate materials | MOTS-c and SS-31 |
PEPTALIAS lists MOTS-c at 10 mg and 40 mg, and SS-31 at 10 mg and 50 mg. Check current availability and format on each listing. If your project compares energy signalling with inner-membrane behaviour, both materials answer different parts of that question; no study here tested them together. A finding for pharmaceutical elamipretide is not a test result for a PEPTALIAS SS-31 vial.
Working on both mechanisms? View MOTS-c and view SS-31. If you are new to the category, start with what a research peptide is; before selecting either vial, use the COA checklist.
PEPTALIAS material is for laboratory research only, not human or veterinary use.
Sources: Lee et al., MOTS-c metabolic study in cells and mice (2015); Reynolds et al., exercise measurements in people and separate mouse experiments (2021); Mitchell et al., SS-31 membrane work (2020); Thompson et al., pharmaceutical elamipretide trial (2021).