Yes. MOTS-c is made naturally from a gene in mitochondrial DNA and has been measured in human blood and muscle. The MOTS-c used in research is a lab-made copy.

In mouse and cell studies, it acted on muscle metabolism, partly through the energy sensor AMPK, and was linked to better insulin sensitivity and exercise capacity.

Has MOTS-c been tested in humans?

Not in published controlled trials. Human studies have mostly measured natural MOTS-c levels, and a modified version called CB4211 was tested in a small early trial.

Is MOTS-c the same as SS-31?

No. Both are linked to mitochondria, but MOTS-c is a natural peptide encoded by mitochondrial DNA, while SS-31 is a lab-designed peptide that targets the inner mitochondrial membrane.

MOTS-c Peptide: What It Is, How It Works, Research and Side Effects

What is MOTS-c?

MOTS-c stands for mitochondrial open reading frame of the 12S rRNA type-c. Mitochondria have their own small set of DNA, separate from the DNA in the cell nucleus. In 2015, a team led by Changhan Lee and Pinchas Cohen at the University of Southern California reported that a short stretch of one mitochondrial gene codes for this 16-amino-acid peptide. It belongs to a small group called mitochondrial-derived peptides, which also includes humanin.

MOTS-c is made naturally in the body and has been measured in blood and muscle. The MOTS-c used in research is a lab-made copy of the natural sequence. Some studies reported lower blood levels in older people, which is one reason it is researched in aging, although results across studies have varied.

How does MOTS-c work?

In cell and mouse studies, MOTS-c acted mainly on skeletal muscle. Researchers reported that it slows part of the folate cycle, which leads to a build-up of a molecule called AICAR. AICAR activates AMPK, an enzyme that works as an energy sensor and helps cells take up glucose and use fat for fuel.

A later study reported that under metabolic stress, MOTS-c moves into the cell nucleus, where it helps control genes involved in stress responses. That was unusual, because it suggests mitochondria can send signals to the nucleus through a peptide. These mechanisms come from lab and mouse research and have not been confirmed in people.

Mixing it for research?

MOTS-c reconstitution chart: how much bacteriostatic water to add to a 5 mg or 10 mg vial and how many units each amount is, with Matthew’s step-by-step video.

See the mixing chart

What has research looked at?

Insulin sensitivity and obesity: In the 2015 study, mice on a high-fat diet treated with MOTS-c gained less weight and had better insulin sensitivity than untreated mice.
Exercise and physical capacity: A 2021 study reported that exercise raised MOTS-c levels in human muscle and blood. In the same work, MOTS-c treatment improved running capacity in young and old mice.
Aging: Mouse research has looked at age-related insulin resistance and physical decline. A study in Japan also linked a variant of the MOTS-c gene with longevity, but association studies cannot show cause and effect.
Bone and other tissues: Some rodent and cell studies have looked at bone loss, heart function and inflammation. These are early findings.
Human trials: A modified version called CB4211 was tested by a company in a small early trial in people with obesity and fatty liver disease. It is not identical to MOTS-c, and its results were preliminary.

The research on MOTS-c is interesting and growing, but most of it is in mice. Human studies so far mostly measure natural MOTS-c levels rather than test it as a treatment. That means its effects in people, good or bad, are not established.

Is MOTS-c an exercise mimetic?

MOTS-c is often called an exercise mimetic or an exercise-induced peptide. The second label has some support, since exercise raised MOTS-c levels in a human study. The first is a hypothesis based on mouse studies, where it activated some of the same pathways as exercise, such as AMPK. Exercise affects the heart, lungs, bones and brain in many ways, and no single molecule has been shown to reproduce those effects in people.

Side effects and cautions

There is little human safety information for MOTS-c itself, because it has not been through published controlled clinical trials. Mouse studies did not report major harms, but they were short and not designed as full safety studies. Effects people describe online, such as irritation where it was injected or fatigue, are anecdotal. Anyone with health questions should talk to a qualified clinician.

Blood sugar: MOTS-c is studied for effects on glucose handling, so its effects alongside diabetes medicines are unknown and could matter.
Long-term effects: No study has followed people using MOTS-c over months or years.
Pregnancy and breastfeeding: There are no safety data, so this is an unknown.
Product content: Peptides sold outside medical settings can differ from their labels in content or purity.