What MOTS-c is
MOTS-c is a short peptide of 16 amino acids, first reported in 2015 by researchers at the University of Southern California. Its name stands for mitochondrial open reading frame of the 12S rRNA type-c. That name describes what makes it unusual: its sequence is encoded not in the cell’s nuclear DNA but within the small, circular mitochondrial genome.
MOTS-c belongs to a group of molecules known as mitochondrial-derived peptides (MDPs), which also includes humanin. The discovery of MDPs challenged the long-held view that mitochondrial DNA encodes only 13 proteins, 22 transfer RNAs and 2 ribosomal RNAs (Lee, Kim & Cohen, Free Radic Biol Med 2016).
The material A&A Wellness supplies as MOTS-c is a synthetic research peptide for laboratory use. It is not a drug, food, cosmetic or supplement, and it is not for human or veterinary use.
Classification and structure
A mitochondrial-derived peptide
Mitochondria are thought to have originated from free-living bacteria and still carry their own genome with its own genetic code. The MOTS-c open reading frame sits inside the gene for the 12S ribosomal RNA. Researchers identified it while searching mitochondrial DNA for short open reading frames, after the earlier discovery of humanin in the 16S rRNA region (Lee et al., Cell Metab 2015).
Sequence and synthetic material
The 16-residue human MOTS-c sequence commonly reported in the literature is MRWQEMGYIFYPRKLR. Research material is made by solid-phase peptide synthesis rather than isolated from biological sources. Several features of the sequence matter for handling:
- Oxidation-sensitive residues. Methionine (two residues) and tryptophan can oxidize.
- Charge. Several basic residues (arginine, lysine) give the peptide a net positive charge at neutral pH.
Identity and purity for a given batch are confirmed by the methods described in our guide to HPLC and mass spectrometry.
Mechanism as described in the literature
The proposed mechanisms of MOTS-c come mainly from cell culture and mouse studies. They should be read as research hypotheses, not established physiology in humans.
Folate cycle and AMPK
In the original 2015 report, Lee and colleagues proposed that skeletal muscle is MOTS-c’s primary target tissue. They reported that its cellular actions inhibit the folate cycle and the linked de novo purine biosynthesis pathway. This leads to accumulation of the metabolite AICAR and activation of AMP-activated protein kinase (AMPK), a central cellular energy sensor (Lee et al., Cell Metab 2015).
Nuclear translocation
A 2018 study in Cell Metabolism reported that under metabolic stress, such as glucose restriction, MOTS-c moves from the cytoplasm into the nucleus in an AMPK-dependent manner. There it was reported to regulate a broad set of nuclear genes, including genes with antioxidant response elements, and to interact with stress-responsive transcription factors such as NRF2 (Kim et al., Cell Metab 2018).
Why it matters: mitonuclear communication. Communication was long thought to run mostly one way, from the nucleus to the mitochondria. The authors proposed that the finding points to genetically integrated communication running from mitochondria to the nucleus as well. This conceptual point is a large part of why MOTS-c attracts research interest.
Research history and key published studies
Discovery (2015)
The founding paper described the identification of the MOTS-c open reading frame, detection of the peptide in cells and tissues, and a series of mouse experiments. The investigators reported that MOTS-c treatment in mice prevented age-dependent and high-fat-diet-induced insulin resistance and diet-induced obesity in those models (Lee et al., Cell Metab 2015).
Early review (2016)
A 2016 review by members of the same group placed MOTS-c within the broader MDP concept. It discussed the idea of mitochondrial-encoded signals acting at both the cellular and whole-organism level, which some authors have called “mitochondrial hormones” (Lee, Kim & Cohen, 2016).
Nuclear signalling (2018)
The 2018 translocation study described above moved the research focus from metabolic readouts toward gene regulation (Kim et al., 2018).
Exercise and ageing models (2021)
In Nature Communications in 2021, Reynolds and colleagues reported experiments in young, middle-aged and old mice. They found that MOTS-c treatment affected measures of physical performance and that it regulated nuclear genes related to metabolism and proteostasis. In a separate human component, the authors reported that exercise increased endogenous MOTS-c levels in skeletal muscle and in circulation (Reynolds et al., Nat Commun 2021). That observation concerns the body’s own peptide measured after exercise. It is not a study of administered MOTS-c in people.
Recent reviews (2023 onward)
Later reviews have catalogued preclinical work on MOTS-c in models of ageing, cardiovascular disease, insulin resistance and inflammation. A 2023 review in Frontiers in Endocrinology noted that no effective method of applying MOTS-c clinically had yet been developed. The authors pointed to synthetic-biology approaches as a direction for future work (Zheng et al., Front Endocrinol 2023).
How MOTS-c is studied
Most published MOTS-c work combines three kinds of experiment:
- Cell culture. Myoblast and other cell lines are used to examine signalling, including AMPK activation and nuclear localization, often with fluorescently tagged or antibody-detected peptide.
- Mouse models. Diet-induced and age-related models are used to examine systemic metabolic readouts.
- Endogenous measurement. Circulating and tissue levels of the body’s own MOTS-c are measured in animals and people, usually with immunoassays.
Assay caveats. Measuring a 16-residue peptide in plasma is technically demanding, and immunoassay specificity is a recurring methodological question for mitochondrial-derived peptides generally. Researchers comparing reported MOTS-c levels across studies should pay close attention to the detection method each study used.
Mitochondrial genetic variation. Human mitochondrial DNA varies between populations, and a naturally occurring variant within the MOTS-c open reading frame has been discussed in the literature as a way to study MOTS-c biology genetically. These genetic studies are observational. They are separate from any experiment that administers the peptide.
A preclinical evidence base. The peer-reviewed evidence on administered MOTS-c comes overwhelmingly from cell and animal studies. We are not aware of published, completed, controlled clinical trials establishing any clinical effect of administered MOTS-c.
Regulatory status
- Not an approved drug. MOTS-c is not FDA-approved for any use, and it is not the active ingredient in any approved medicine.
- Compounding status is in flux. FDA’s treatment of certain peptides as bulk substances for pharmacy compounding has been under active review, and MOTS-c was among the peptides discussed in 2026. Those proceedings concern compounding pharmacies. They do not make MOTS-c an approved drug and do not change the status of research-grade material.
- Research material only. A&A Wellness’s MOTS-c is supplied only for laboratory research, not for human or veterinary use.
For general background, see our research peptides regulatory overview. It is not legal advice.
Handling and storage in the lab
- Lyophilized storage. Keep sealed vials cold, dry and protected from light. Freezer storage is a common convention for long-term holding of lyophilized peptides.
- Limit oxidation. Because the sequence contains methionine and tryptophan, minimize exposure of both powder and solutions to air and light. Many laboratories use degassed or freshly prepared diluents and close vials promptly.
- Equilibrate, then open. Allow the vial to reach room temperature while sealed before opening, to prevent condensation.
- Aliquot solutions. Refrigerate or freeze aliquots according to your SOPs, avoid repeated freeze-thaw cycles, and label each with the date and concentration.
See our peptide storage guide and what are research peptides? for background.
Research-use notice
All A&A Wellness products are for research use only. They are not for human or veterinary use and are not a drug, food, cosmetic or dietary supplement. This page describes published laboratory and animal research. It does not suggest that MOTS-c has any established effect in people or should be used by anyone. Please read our Research Use Policy before ordering.
Related resources
- Product page: MOTS-c
- Related compounds: SS-31, another mitochondria-focused research peptide; NAD+
- Category: Research Peptides
- Quality: Our quality standards
Sources
- Lee C, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443-454.
- Lee C, Kim KH, Cohen P. MOTS-c: A novel mitochondrial-derived peptide regulating muscle and fat metabolism. Free Radic Biol Med. 2016;100:182-187.
- Kim KH, et al. The Mitochondrial-Encoded Peptide MOTS-c Translocates to the Nucleus to Regulate Nuclear Gene Expression in Response to Metabolic Stress. Cell Metab. 2018;28(3):516-524.
- Reynolds JC, et al. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nat Commun. 2021;12(1):470.
- Zheng Y, et al. MOTS-c: A promising mitochondrial-derived peptide for therapeutic exploitation. Front Endocrinol (Lausanne). 2023;14:1120533.
