MOTS-c and Mitochondrial Peptides: Mechanism, Evidence and Status

MOTS-c belongs to a group of molecules that have revolutionized our understanding of the mitochondrion over the past decade. It has been discovered that the mitochondrial genome encodes not only respiratory chain proteins, but also short signaling peptides—messages sent by the mitochondrion to the rest of the cell and to other tissues.

This is indeed an interesting area of research. However, it is important to put things into perspective right away: all of this knowledge comes from cellular and animal models, and no clinical trials involving humans have been conducted. The article describes the mechanism and the current state of the evidence; it does not include dosages or administration regimens.

All substances discussed in the article are for research purposes only and are not intended for human consumption. The description of their effects is based solely on laboratory results and experimental observations, not on clinical trials.

What Are Mitochondrial-Derived Peptides?

The mitochondrion has its own small genome—a remnant attesting to the bacterial origin of this organelle. For decades, it was assumed that this genome encoded only components of the respiratory machinery. The discovery of mitochondrial-derived peptides (MDP) changed this picture: short open reading frames have been identified within mitochondrial genes, and their products perform signaling functions.

These molecules are sometimes referred to as mitokines—by analogy with cytokines, which are intercellular signaling molecules. Their role in the context of mitochondrial stress and aging processes is summarized in a review article (Burtscher et al., 2023, PMID 36642986), and the relationship of this entire group to physical exercise is discussed separately (Woodhead and Merry, 2021, PMID 34520826).

MOTS-c is the best-characterized member of this group—alongside humanin and peptides from the SHLP family.

Mechanism

Pioneering Study

The peptide was described in 2015 in Cell Metabolism. It was demonstrated at that time that MOTS-c influences metabolic homeostasis and reduces obesity and insulin resistance in a mouse model (Lee et al., 2015, PMID 25738459). This publication is the source of most of the claims circulating today about MOTS-c—it is therefore worth noting the model in which the study described therein was conducted.

Molecular Target

For years, the mechanism was generally described in terms of the AMPK pathway—the cell’s energy sensor. More recent data are more precise: a study published in iScience demonstrated that MOTS-c modulates skeletal muscle function through direct binding to and activation of casein kinase 2 (CK2) (Kumagai et al., 2024, PMID 39559755). This finding is significant because it identifies a specific target protein rather than a general pathway.

The role of MOTS-c in cell membrane repair by facilitating the transport of the TRIM72 protein to the site of damage has also been described (Jia et al., 2024, PMID 39267782).

Research Rationale

The research logic behind this group of compounds is consistent: if a mitochondrion sends a signal indicating its energy status, and this signal triggers an adaptive response in the muscle and liver, then administering such a peptide externally could elicit that response. Hence the term “exercise mimetic”, which is associated with this category.

However, this term describes a research hypothesis, not a proven effect in humans. The exercise-induced signal arises within the tissue, at a specific concentration and within a specific metabolic context—which is not the same as administering the same molecule externally.

Data From Animal and Cellular Models

All observations in this section come from animal studies or cell cultures. There are no human studies confirming these observations.

• Metabolism and insulin sensitivity — in a mouse model, effects on metabolic homeostasis, adipose tissue mass, and insulin resistance have been described (PMID 25738459).
• Immobilization-induced muscle atrophy — a reduction in immobilization-induced skeletal muscle atrophy was demonstrated, accompanied by a decrease in fat infiltration (Kumagai et al., 2024, PMID 38170165).
• Glucose metabolism — effects on hyperglycemia and insulin resistance have been described in a model of gestational diabetes (Yin et al., 2022, PMID 34798268).
• Cancer research — the effect on ovarian cancer progression via a deubiquitination-related mechanism was investigated (Yin et al., 2024, PMID 39321430). This finding indicates that the peptide’s biological activity extends beyond metabolism.

The current state of knowledge regarding this entire group is summarized in a review article (Zheng et al., 2023, PMID 36761202).

What the Data Do Not Show

• They do not demonstrate efficacy in humans. No clinical trials evaluating MOTS-c for any indication have been published.
• They do not demonstrate pharmacokinetics in humans. It is unknown how the peptide behaves after administration in humans.
• They do not show a safety profile. It has not been established for any time horizon.
• They do not show equivalence to physical exercise. The term “exercise mimetic” describes a research direction, not a demonstrated effect.

It is worth noting an observation that is sometimes overlooked when it comes to endogenous peptides: the endogenous origin of a molecule does not guarantee the safety of its exogenous administration. A signal generated locally in response to a specific stimulus differs from a signal triggered by the same molecule introduced into the circulation—in terms of concentration, timing, and tissue context.

Regulatory Status and Anti-Doping Note

MOTS-c is not registered as a medicinal product in any jurisdiction. It is not a dietary supplement or a food product and is not subject to health claims. A broader context of approved and unapproved peptide therapies is discussed in a 2026 review (Mendias and Awan, 2026, PMID 41966639).

Anti-Doping Note: MOTS-c is not specifically listed by name on the WADA Prohibited List. However, this does not mean it is permitted—a provision applies to substances with a similar chemical structure or similar biological effect, and signaling peptides with metabolic effects may be evaluated under categories S2 or S4.4. The current rules are available in the WADA Prohibited List and should be checked against the version in force.

Harm Reduction

• The safety profile in humans has not been established — therefore, it cannot be assessed as either beneficial or harmful.
• Biological activity extends beyond metabolism. Effects on cell proliferation and repair processes have been described, meaning that the effects are not limited to the intended area.
• Endogenous does not mean inert. A molecule produced by the body in a specific context is not equivalent to the same molecule administered externally.
• The identity of the material is determined by the batch documentation — we discuss this topic in the article How to Read a Certificate of Analysis.

Frequently Asked Questions

Is MOTS-c an “exercise mimetic”?

The term describes a research hypothesis, not a proven effect in humans. It stems from the observation that this peptide participates in metabolic signaling triggered, among other things, by exercise. Exogenous administration of the molecule is not equivalent to the signal generated within the tissue.

Are there any studies on MOTS-c in humans?

No clinical trials evaluating the efficacy or safety of this peptide in humans have been published. The available data come from animal models and cell cultures.

Since the body produces it on its own, isn’t it safe?

Endogenous origin is not a guarantee of safety when administered externally. What matters is the concentration, the site of production, and the metabolic context in which the signal occurs.

What is the molecular target of MOTS-c?

For years, it was generally described in terms of its role in the AMPK pathway. More recent data indicate direct binding to and activation of casein kinase 2 (CK2) in skeletal muscle (PMID 39559755).

Why doesn’t the article specify dosages?

Because MOTS-c has not undergone any human studies in which dosing was determined. The dosage values currently in circulation do not come from clinical trials.

Summary

MOTS-c is a peptide encoded by the mitochondrial genome and the best-characterized member of a group known as mitokines—signals sent by the mitochondria to the rest of the body. Most of the claims surrounding this compound stem from a study published in 2015 in Cell Metabolism, conducted in a mouse model, which described its effects on metabolic homeostasis, body fat mass, and insulin resistance. More recent studies have clarified the mechanism, pointing to the direct binding and activation of casein kinase 2 in skeletal muscle, and have described the peptide’s role in cell membrane repair and in limiting immobilization-induced muscle atrophy—all in animal and cellular models. No clinical trials involving humans have been conducted, so there are no data on efficacy, pharmacokinetics, or safety. The term “exercise mimetic” describes a line of research, not a proven effect, and the endogenous origin of the molecule does not guarantee the safety of its exogenous administration.

Product Documentation

Research data sheets, along with batch analytical documentation, are available in two versions: vial and 20 mg pen. We discuss the guidelines for working with lyophilized material in the article on bacteriostatic water. Materials intended for research use only.

Bibliography

1. Lee C, Zeng J, Drew BG, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443–454. PMID: 25738459
2. Kumagai H, Kim SJ, Miller B, et al. MOTS-c modulates skeletal muscle function by directly binding and activating CK2. iScience. 2024;27(11):111212. PMID: 39559755
3. Kumagai H, Kim SJ, Miller B, et al. Mitochondrial-derived microprotein MOTS-c attenuates immobilization-induced skeletal muscle atrophy by suppressing lipid infiltration. Am J Physiol Endocrinol Metab. 2024;326(3):E207–E214. PMID: 38170165
4. Jia H, Zhou LC, Chen YF, et al. Mitochondria-encoded peptide MOTS-c participates in plasma membrane repair by facilitating the translocation of TRIM72 to membrane. Theranostics. 2024;14(13):5001–5021. PMID: 39267782
5. Yin Y, Pan Y, He J, et al. The mitochondrial-derived peptide MOTS-c relieves hyperglycemia and insulin resistance in gestational diabetes mellitus. Pharmacol Res. 2022;175:105987. PMID: 34798268
6. Yin Y, Li Y, Ma B, et al. Mitochondrial-Derived Peptide MOTS-c Suppresses Ovarian Cancer Progression by Attenuating USP7-Mediated LARS1 Deubiquitination. Adv Sci (Weinh). 2024;11(43):e2405620. PMID: 39321430
7. Zheng Y, Wei Z, Wang T. MOTS-c: A promising mitochondrial-derived peptide for therapeutic exploitation. Front Endocrinol (Lausanne). 2023;14:1120533. PMID: 36761202
8. Woodhead JST, Merry TL. Mitochondrial-derived peptides and exercise. Biochim Biophys Acta Gen Subj. 2021;1865(12):130011. PMID: 34520826
9. Burtscher J, Soltany A, Visavadiya NP, et al. Mitochondrial stress and mitokines in aging. Aging Cell. 2023;22(2):e13770. PMID: 36642986
10. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Med. 2026;56(8):1921–1935. PMID: 41966639