Mitochondrial research
MOTS-c and SS-31 are not the same kind of peptide.
Both appear in mitochondrial research. Their origin, sequence and experimental questions are different.
Research context reviewed 3 September 2026MOTS-c
MOTS-c is a 16-amino-acid peptide encoded by a short open reading frame within mitochondrial 12S rRNA. Its 2015 discovery paper used cellular and mouse models to examine mitochondrial communication and metabolic signalling.
That makes MOTS-c part of the developing field of mitochondrial-derived peptides: sequences encoded within mitochondrial DNA that may act beyond the organelle where they originate.
SS-31 / Elamipretide
SS-31 is a synthetic aromatic-cationic tetrapeptide, also called elamipretide. It is not mitochondrially encoded. Biophysical research has instead examined how the peptide interacts with lipid bilayers and cardiolipin-containing mitochondrial membranes.
A 2020 study reported partitioning at the membrane interface and changes in lipid packing and surface electrostatics without broad bilayer disruption.
Why the distinction matters
“Mitochondrial peptide” describes a research context, not a shared sequence or interchangeable material. MOTS-c research begins with a mitochondrially encoded signalling peptide. SS-31 research begins with a designed tetrapeptide and membrane biophysics.
Results from one should not be transferred to the other—or to a commercial material that was not part of the cited study.