MOTS-c is a 16-amino-acid peptide encoded in the mitochondrial genome rather than the nuclear one. Part of a small class of mitochondrial-derived peptides identified over the last fifteen years.

The biology is genuinely interesting: it appears to function as a signalling molecule communicating mitochondrial status to the rest of the cell, and it is among the clearer examples of retrograde mitochondrial-to-nuclear signalling. Whether that makes it a therapeutic is an entirely separate question that nobody has answered, and this entry exists partly to hold that distinction open.

MOTS-c is described as regulating metabolic homeostasis partly through the folate. Methionine cycle and AICAR accumulation, leading to AMPK activation. It has also been reported to translocate to the nucleus under metabolic stress and influence expression of stress-response genes.

In mouse models it has been associated with improved insulin sensitivity, resistance to diet-induced obesity, and exercise-capacity effects. Human circulating levels have been reported to vary with age and metabolic status in observational work. Which establishes association, not direction of causation.

Mechanistic and preclinical. There is no completed randomised controlled trial in humans reporting outcomes.

The mouse data is reasonably consistent for metabolic endpoints and comes from more than one group, which is a better position than several other entries here. Human work is observational: circulating MOTS-c concentrations correlate with age, metabolic parameters, and exercise in cross-sectional studies.

An observed correlation between a peptide's concentration and a health state does not establish that administering it produces that state. This is the specific inference the compound's popular framing depends on, and it has not been tested.

No human safety data. No characterised toxicology in humans, no immunogenicity data, no long-term exposure data of any kind.

Because it acts on AMPK and metabolic signalling, pathways that also intersect with cell growth and survival, the theoretical concerns include effects on undiagnosed malignancy and unpredictable interaction with metabolic disease and its treatments.

Material sold for this is research-grade with unverified identity and purity. Given the sequence is short and public, mis-synthesis and degradation are practical concerns as much as regulatory ones.

Not approved anywhere. No registered interventional trial has reported results. Sold as a research chemical.