MOTS-c

MOTS-c is a 16-amino-acid peptide encoded within the 12S ribosomal RNA gene of the mitochondrial genome — the first mitochondrial-encoded peptide to be characterized as a circulating signaling molecule rather than a structural component of the organelle. The discovery and primary characterization, by Changhan Lee and Pinchas Cohen at the University of Southern California, established a metabolic signaling pathway distinct from any known nuclear-encoded peptide hormone ([Lee et al., *Cell Metab* 2015, 21:443–454](https://doi.org/10.1016/j.cmet.2015.02.009)). MOTS-c's primary tissue target appears to be skeletal muscle, where it inhibits the folate cycle, raises AICAR levels, and activates AMP-activated protein kinase (AMPK). AMPK activation downstream produces increased glucose uptake, fatty-acid oxidation, and the broader metabolic effects associated with the cellular energy-stress response. Subsequent work from the Cohen group showed that MOTS-c can translocate to the nucleus under metabolic stress and regulate nuclear gene expression — a mitochondria-to-nucleus signaling axis that adds mechanism beyond simple peripheral hormone-like activity.

MOTS-c is the longevity-and-mitochondrial-health peptide whose biology is the most novel on this site. Its value to the corpus is partly the molecule itself and partly the biology it represents: mitochondrial-derived peptides as a signaling class, with MOTS-c the most-studied first member. The published mouse work (Lee et al. 2015) is striking. In mice, MOTS-c administration prevented age-dependent and high-fat-diet-induced insulin resistance, improved glucose tolerance, lowered circulating insulin levels, and increased glucose uptake in skeletal muscle. Subsequent papers from the same and adjacent groups have extended the phenotype to exercise capacity, age-related cognitive decline, and metabolic responses across multiple tissues. The broader mitochondrial-derived peptide field has expanded to include humanin, SHLP1-6, and other 12S- and 16S-encoded fragments that share signaling-molecule properties. The clinical translation is essentially absent. There are no large randomized human trials of exogenous MOTS-c for any indication. Some early-phase observational and pilot work exists; serum MOTS-c levels have been correlated with metabolic and aging biomarkers in human cohorts, but those correlations don't establish that exogenous administration produces equivalent benefits in humans. The biohacker market in injectable MOTS-c rests primarily on the rodent metabolic and longevity literature plus the broader appeal of "mitochondrial health" as a category, with the corresponding sourcing-quality concerns the site declines to relitigate. The honest framing is that MOTS-c is one of the most genuinely interesting discoveries in metabolic-peptide biology of the past decade and one of the peptides with the largest gap between published basic science and tested human application. Anyone considering use should be reading the Lee 2015 paper, not the marketing summaries of it, and should be candid about acting on rodent inference rather than human evidence.