MOTS-c: a peptide written in mitochondrial DNA, and the fine print
The short version: MOTS-c is a 16-amino-acid peptide with an unusual address. Its code sits inside the mitochondria’s own DNA, tucked into a gene called 12S rRNA, rather than in the cell nucleus with almost everything else. A 2015 paper in Cell Metabolism found that it stopped mice on a high-fat diet from becoming obese and insulin resistant. In people the record is much thinner: it can be measured in blood, it rises with exercise, a modified version had one short trial, and the first placebo-controlled trial of MOTS-c itself is only now recruiting.
A gene hiding inside another gene
Mitochondria carry a small genome of their own, separate from the DNA in the nucleus. It was traditionally thought to hold just 13 protein-coding genes. Then researchers found humanin, a signalling peptide coded by a short stretch of mitochondrial DNA, and started looking for more.
In 2015, Changhan Lee, Pinchas Cohen and colleagues at the University of Southern California reported another one. Inside the gene for 12S rRNA, they found a short open reading frame, a small stretch that can be read as a recipe for a peptide. They named the result MOTS-c, short for mitochondrial open-reading-frame of the twelve S rRNA-c. It is 16 amino acids long, and its first 11 are highly conserved across the 14 species they compared. They detected it in rodent tissues and in human and rodent blood plasma.
What it did in mice
In cells, MOTS-c slowed the folate cycle and the purine-building pathway tied to it. That raised levels of a molecule called AICAR, which switches on an enzyme called AMPK (AMP-activated protein kinase). The main target organ looked to be skeletal muscle.
The headline result came from mice fed a high-fat diet. Mice given MOTS-c did not become obese the way untreated mice did, even though both groups ate the same amount. The treatment also prevented the rise in insulin that the diet caused. On a normal diet it made no difference to body weight. In a separate test, muscle from middle-aged mice was more insulin resistant than muscle from young mice, and a week of MOTS-c brought it back to young levels.
The exercise paper
A 2021 follow-up in Nature Communications, with Changhan Lee as senior author, found that MOTS-c improved physical performance in young, middle-aged and old mice. Treatment started late in life, at around 23.5 months, improved grip strength, stride and a walking test in very old mice.
It also had the first human data worth talking about. Ten sedentary, healthy young men rode a stationary bike. MOTS-c in their thigh muscle rose 11.9-fold after exercise, and blood levels rose 1.6-fold during exercise and 1.5-fold after it, then drifted back to baseline after four hours of rest. The key detail: nobody was given MOTS-c. This measured the body’s own peptide responding to exercise.
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| Study | Who or what | What it found |
|---|---|---|
| Lee et al., 2015 | Cells and mice | Prevented diet-induced obesity and insulin resistance in mice |
| Reynolds et al., 2021 | Mice, plus 10 young men who were not given it | Better physical performance in mice; the men’s own levels rose with exercise |
| CohBar CB4211, 2021 | 20 adults with obesity and fatty liver, four weeks, a modified version | Liver enzymes fell against placebo; liver fat fell in both groups alike |
| Phase 2a trial, NCT07505745 | About 120 adults with prediabetes, planned | Recruiting; no results yet |
The human trials so far
The only completed treatment trial we could find on ClinicalTrials.gov used CB4211, which its maker CohBar described as an improved analogue of MOTS-c. That is a close cousin, not the same molecule. After a safety stage in 65 healthy adults, the company ran a four-week, placebo-controlled stage in 20 people with obesity and fatty liver, who stayed in the clinic for the whole study.
The company’s August 2021 release reported no serious adverse events and significant falls in the liver enzymes ALT and AST, plus a fall in blood glucose, against placebo. Body weight showed only a trend. Liver fat dropped by about the same amount in both groups, so the drug did not separate from placebo there. These were topline numbers in a press release, from a short trial with very small groups.
The first registered controlled trial of MOTS-c itself is a phase 2a study sponsored by Hudson Biotech. It aims to enrol around 120 adults with prediabetes and overweight, measures insulin sensitivity against placebo, started in February 2026, and has an estimated primary completion date of February 2027.
If you remember one thing: the striking MOTS-c results are in mice, the human data so far is measurement plus one short trial of a modified version, and the first real placebo-controlled trial has not reported.
Why sport bans it
The 2026 World Anti-Doping Agency Prohibited List, as reproduced by the German Sport University Cologne, names MOTS-c under hormone and metabolic modulators, as an example of an AMPK activator. It sits in the same entry as AICAR, the molecule the 2015 paper found it raises. Athletes in tested sport should treat it as off limits.
Where the evidence stops
- The big effects are in mice. Obesity, insulin resistance and physical performance results all come from animal work, much of it from one research network.
- The human exercise data is observational. It shows the body makes more MOTS-c during exercise. It says nothing about what added MOTS-c does in a person.
- The only finished trial used a different molecule. CB4211 is an analogue, the trial lasted four weeks, and liver fat did not differ from placebo.
- The real test is still running. Until the phase 2a trial reports, there is no placebo-controlled human result for MOTS-c itself.
A note on framing
Nothing here shows what MOTS-c does in a person, because that trial has not finished. A mouse result is a reason to run a human trial, not a stand-in for one, and an analogue trial is not a MOTS-c trial. We sell to researchers, and we would rather you read the papers than a forum thread.
Where JP fits
JP Research supplies MOTS-c as research-grade freeze-dried powder, for laboratory research use only. An independent Janoshik lab report for a MOTS-c batch is linked on the product page. Orders are dispatched within 1 to 3 business days, with free courier across South Africa. If you are comparing metabolic compounds, our piece on 5-Amino-1MQ and NAD+ covers two more, and our reconstitution and storage guide covers handling.
Browse the metabolic research range →
Sources
- Lee et al.: The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance (Cell Metab, 2015)
- Reynolds et al.: MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis (Nat Commun, 2021)
- CohBar: topline results from the phase 1a/1b study of CB4211 (press release, August 2021)
- ClinicalTrials.gov: phase 2a trial of MOTS-c in adults with prediabetes and overweight (NCT07505745)
- German Sport University Cologne: S4 hormones and metabolic modulators, WADA Prohibited List 2026
Plain-English guides on Peptide Carl: MOTS-c and the Mitochondrial Tune-Up stack. Carl is the free education site we run.
All JP Research products are supplied strictly for in-vitro research and laboratory use only. They are not intended for human or animal consumption, medical treatment, or diagnostic use. Nothing in this article constitutes medical advice.