MOTS-c
A 16-amino-acid mitochondrial-derived peptide studied in preclinical models for AMPK activation, insulin sensitivity, and exercise-mimetic metabolic effects.
Reviewed by Mei Li, PhD, Chief Science Officer
What MOTS-c is
MOTS-c (mitochondrial open reading frame of the 12S rRNA type-c) is a 16-amino-acid mitochondrial-derived peptide (MDP) encoded within a short open reading frame of the mitochondrial 12S rRNA gene, MT-RNR1. It was first characterized in 2015 by a University of Southern California team (Lee et al., Cell Metabolism) and belongs to a small family of peptides—alongside humanin and the SHLPs—encoded by the mitochondrial genome rather than the nucleus. Its discovery is significant to mitochondrial biology because it demonstrated that the mitochondrion can generate its own signaling peptides that influence whole-cell and, in animal models, whole-organism metabolism.
How the research describes its mechanism
In preclinical systems, MOTS-c is reported to act primarily through the AMPK energy-sensing pathway. The 2015 work described it inhibiting the folate-methionine cycle and its linked de novo purine synthesis, generating a metabolic signal (accumulation of AICAR) that activates AMPK and is associated with increased glucose uptake and fatty-acid oxidation in skeletal muscle. Kim et al. (2018, Cell Metabolism) subsequently reported that metabolic stress triggers MOTS-c to move from the mitochondria into the nucleus, where it engages antioxidant-response-element (NRF2/ARE) gene programs—an example of retrograde mitochondria-to-nucleus signaling. Downstream effects on insulin sensitivity, GLUT4, and mitochondrial bioenergetics are generally framed as AMPK- and PGC-1alpha-dependent.
The exercise-mimetic framing
MOTS-c draws particular interest because its levels respond to exercise. Reynolds et al. (2021, Nature Communications) reported that acute exercise raised skeletal-muscle MOTS-c expression and circulating peptide in a small human cohort, and that administering MOTS-c improved running capacity and muscle homeostasis in aged mice. This is the basis for its popular 'exercise-mimetic' label. It is important to read this evidence precisely: the performance and healthspan findings are from rodents, while the human data are observational biomarker measurements showing that exercise induces the endogenous peptide—not evidence that administering MOTS-c produces those outcomes in people.
State of human evidence
Direct human efficacy data for native MOTS-c are sparse. The most advanced clinical program involves CB4211, a stabilized MOTS-c analog developed by CohBar, which was reported as the first mitochondrial-derived peptide therapeutic to reach clinical testing. Its Phase 1a/1b study was explored in the context of NASH (fatty liver disease) and obesity and was described as generally well-tolerated over a short treatment period. Because CB4211 is an engineered analog with altered stability, its results cannot be directly attributed to native MOTS-c. As of mid-2026, the human evidence base for MOTS-c itself remains early and largely biomarker-level.
Regulatory status
MOTS-c is one of exactly seven compounds on the FDA Pharmacy Compounding Advisory Committee (PCAC) docket for July 23-24, 2026, alongside BPC-157, TB-500, KPV, emideltide, epitalon, and semax. At that meeting the committee will cast a non-binding vote on whether to recommend moving MOTS-c toward the 503A Bulks List (Category 1, compoundable with a prescription). It is important to understand what this does and does not mean: the vote is advisory only and represents roughly the second of about six steps in FDA rulemaking. Even a unanimous favorable vote would not make MOTS-c legally available through compounding on its own, and a realistic timeline to any legal compounding availability is at least 12-18 months after a positive vote. MOTS-c is not FDA-approved as a finished drug, and it is best described today as unscheduled / research-use-only, currently Category 2 pending this review. Regulatory reviewers have flagged limited human effectiveness data and insufficient human safety data—including unassessed immunogenicity—for the proposed largely injectable routes.
How to interpret this profile
The MOTS-c literature is a good example of a compound with a compelling, mechanistically detailed preclinical story and a genuinely thin human evidence base. AMPK activation, retrograde nuclear signaling, and exercise responsiveness are well-documented in cells and rodents; translation to human physiology is an open question. This profile is educational and reflects only what published research has examined. It does not describe dosing, does not recommend human use, and should not be read as a safety endorsement.
Key published studies
| Study | Journal | Year | Finding |
|---|---|---|---|
| The Mitochondrial-Derived Peptide MOTS-c Promotes Metabolic Homeostasis and Reduces Obesity and Insulin Resistance | Cell Metabolism | 2015 | Lee et al. First description of MOTS-c; reported AMPK activation via the folate-methionine cycle and improved insulin sensitivity in mouse models. |
| MOTS-c Is an Exercise-Induced Mitochondrial-Encoded Regulator of Nuclear Gene Expression | Cell Metabolism | 2018 | Kim et al. Reported that metabolic stress drives MOTS-c translocation to the nucleus, where it regulates antioxidant-response (NRF2/ARE) genes—evidence of retrograde mito-to-nuclear signaling. |
| MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis | Nature Communications | 2021 | Reynolds et al. Exercise raised endogenous MOTS-c in a small human cohort; MOTS-c administration improved running capacity and muscle homeostasis in aged mice (preclinical efficacy). |
| Mitochondria-derived peptide MOTS-c: effects and mechanisms related to stress, metabolism and aging | Journal of Translational Medicine | 2023 | Review summarizing preclinical mechanisms across metabolism, stress response, and aging, and noting the limited state of human data. |
Regulatory status
Current status: Category 2 · PCAC July 2026 docket. Category 2 · PCAC July 2026 docket. PepSense tracks FDA filings and updates this record as the regulatory picture changes. See the FDA PCAC tracker for the July 2026 vote and what happens next.