MOTS-C is a short peptide encoded not in the nuclear genome but within the 12S ribosomal RNA gene of mitochondrial DNA. It was first characterized in 2015 by Changhan Lee, Pinchas Cohen, and colleagues at the University of Southern California, who showed that the peptide acts as a hormone-like signal regulating whole-body metabolism. For a plain-language introduction, see our MOTS-C mitochondrial peptide guide.
In skeletal muscle, the peptide activates AMP-activated protein kinase (AMPK) and shifts cellular metabolism toward glucose uptake and fatty-acid oxidation — the same program switched on by exercise and caloric restriction. That overlap is why the literature so often describes it as an “exercise mimetic.”
Sequence and Structure
The 16-residue sequence MRWQEMGYIFYPRKLR carries four basic residues (two arginines near the C-terminus, one lysine, and the N-terminal-adjacent arginine) against a single glutamate, giving the molecule a net positive charge at physiological pH. A cluster of aromatic residues — tryptophan at position 3 and tyrosine or phenylalanine at positions 8, 10, and 11 — creates an amphipathic character that is thought to support membrane association and nuclear import.
Two methionines, at positions 1 and 6, are the chemically weakest points of the molecule and the reason oxidation is the main degradation route to watch for. The naturally occurring K14Q variant discussed below replaces the lysine at position 14 with a neutral glutamine, removing one positive charge; that single substitution is enough to change the peptide’s measured metabolic activity, which illustrates how sequence-sensitive this class of molecules is.
Detailed Mechanism of Action
Understanding the multi-target mechanism is essential before you buy MOTS-C for a study, because the readouts differ by tissue and by timing. The best-characterized effect is activation of AMPK in skeletal muscle, which increases glucose uptake, promotes fatty-acid oxidation, and stimulates mitochondrial biogenesis. These are the hallmarks of the metabolic state produced by endurance exercise.
Upstream of AMPK, the peptide inhibits the folate cycle and de novo purine biosynthesis. The resulting accumulation of AICAR — an endogenous AMPK activator — is the proposed link between one-carbon metabolism and the kinase. This reprogramming steers muscle cells away from anabolic pathways and toward energy production, which is why changes in substrate utilization can be measured within hours in cell culture.
The third mechanism is nuclear translocation. In 2018, Kim and colleagues showed that under glucose restriction or oxidative stress, MOTS-C moves from the mitochondria into the nucleus, where it associates with antioxidant response elements and transcription factors such as NRF2 to regulate stress-adaptive genes. This established a retrograde signaling route from the mitochondrial genome to the nuclear genome that had not previously been described in mammals.
Downstream, the MOTS-C peptide has been linked to SIRT1/PGC-1α signaling, reduced inflammatory cytokine output, and preservation of mitochondrial membrane potential. More recent work from Kumagai and colleagues (2024) reports direct binding to and activation of casein kinase 2 (CK2) in muscle, adding a kinase-level target to the AMPK-centred model. Together these pathways explain why the peptide is studied across metabolism, aging, and exercise physiology.
Published Research on MOTS-C
The foundational study by Lee et al. (2015, Cell Metabolism) identified the peptide and showed that systemic administration in mice prevented and reversed diet-induced obesity and insulin resistance, reduced fat accumulation, and improved skeletal-muscle insulin sensitivity. This paper remains the reference point for most experimental designs in the field.
Kim KH et al. (2018, Cell Metabolism) demonstrated nuclear translocation in response to metabolic stress and its role in regulating nuclear gene expression. In 2019, Lu et al. reported in the Journal of Molecular Medicine that MOTS-C treatment prevented ovariectomy-induced metabolic dysfunction in female mice, prompting the accompanying commentary “MOTS-c: an equal opportunity insulin sensitizer” (Kim SJ et al., 2019).
Reynolds JC et al. (2021, Nature Communications) showed that plasma MOTS-C rises with acute exercise in humans, declines with age in mice, and that late-life treatment improved physical capacity and healthspan markers in aged animals. The study positions the peptide as both an exercise-responsive signal and a candidate target for sarcopenia research.
Human genetics adds another layer. Fuku et al. (2015, Aging Cell) described the m.1382A>C variant, which produces a K14Q substitution in the peptide and is enriched in long-lived Northeast Asian populations, while Zempo et al. (2021, Aging) linked the same variant to higher type 2 diabetes risk in carriers with low physical activity. D’Souza et al. (2020) also found higher MOTS-C expression in the skeletal muscle of healthy older men, associated with myofiber composition. These findings make it a useful bridge between population genetics and bench experiments.
Observational human data are accumulating as well. Sequeira et al. (2021) measured plasma mitochondrial-derived peptides in adults without diabetes and found that circulating levels associated with android and liver fat, suggesting the peptide responds to metabolic load rather than simply tracking age. A synthetic analog, CB4211, also advanced into early-phase clinical testing for non-alcoholic fatty liver disease and obesity, which is the first time a molecule in this class reached human trials. For bench researchers, these developments mean the field is moving from discovery toward translational questions, and well-characterized reference material matters more than ever.
MOTS-C vs Other Mitochondrial Peptides
| Feature | MOTS-C | Humanin | SHLP2 |
|---|
| Encoding gene | mtDNA 12S rRNA | mtDNA 16S rRNA | mtDNA 16S rRNA |
| Length | 16 amino acids | 24 amino acids | 26 amino acids |
| Primary target | AMPK / folate–AICAR axis | Apoptosis, neuroprotection | Mitochondrial function, ROS |
| Exercise mimetic | Yes — well documented | Not established | Limited data |
| Nuclear translocation | Yes (stress-induced) | No | Not reported |
| Aging research | Extensive (2015–present) | Extensive (2001–present) | Early stage |
| Metabolic disease data | Strong (obesity, insulin resistance) | Moderate | Emerging |
| Available at PSPeptides | 10 mg and 50 mg vials | — | — |
Choosing the 10 mg or 50 mg Vial
Both sizes contain the same ≥99% peptide; the only difference is how much lyophilized material is in the vial. The 10 mg vial suits pilot studies, dose-finding, and short in vitro series where opening a fresh vial for each experimental window minimizes waste. The 50 mg vial is the economical choice for multi-week animal studies, large-plate cell work, or any protocol where aliquoting from one well-characterized lot improves consistency. Many laboratories that buy MOTS-C for an ongoing program standardize on the 50 mg vial so every arm of a study shares the same batch and COA.
Experimental Design Notes
Published in vitro work typically uses low-micromolar concentrations (around 1–10 μM) in C2C12 myotubes or HEK293 cells, with AICAR accumulation and AMPK phosphorylation as early readouts. Rodent studies span roughly 0.5–15 mg/kg, administered daily or several times per week, with glucose tolerance, body composition, and treadmill or grip-strength endpoints. Because the circulating half-life is short, dosing frequency matters more than peak concentration in most designs. These figures are cited from the literature for protocol planning and are not recommendations for any non-research use.
Common Laboratory Assays and Readouts
The most direct confirmation of activity is AMPK phosphorylation at Thr172 by western blot, usually paired with phosphorylation of its substrate ACC. Because the proposed upstream event is folate-cycle inhibition, many groups also quantify intracellular AICAR by LC-MS or measure de novo purine synthesis with labeled precursors. Glucose uptake is read out with 2-deoxyglucose or 2-NBDG assays in differentiated C2C12 myotubes, and oxygen consumption and extracellular acidification rates on a Seahorse analyzer capture the shift toward oxidative metabolism.
Nuclear translocation experiments typically combine glucose restriction or serum deprivation with subcellular fractionation or immunofluorescence against a tagged peptide, followed by chromatin immunoprecipitation at antioxidant-response-element promoters. In vivo, standard endpoints are glucose and insulin tolerance tests, body composition by EchoMRI or DEXA, indirect calorimetry, and functional measures such as treadmill endurance and grip strength. Plasma levels of the endogenous peptide are measured by ELISA, and the exercise-induced rise reported by Reynolds and colleagues makes timing of blood collection relative to activity an important design variable.
Reconstitution & Handling
Reconstitute with bacteriostatic water. A common starting point is 2 mL for the 10 mg vial, giving a 5 mg/mL stock; for the 50 mg vial, 2.5 mL gives 20 mg/mL — the vial holds 3 mL, so that is as dilute as it goes. Run the solvent slowly down the inside wall of the vial rather than onto the powder cake, then swirl gently until clear — never shake or vortex. Our peptide reconstitution guide and dosage calculator cover other volumes, and our bacteriostatic water explainer covers why it is preferred over sterile water for multi-draw vials.
Use low-protein-binding plasticware to limit adsorption to tube walls, and keep solutions in amber or foil-wrapped tubes to limit light exposure. The two methionine residues at positions 1 and 6 are oxidation-prone, so avoid leaving reconstituted MOTS-C open to air or at room temperature for extended periods. For multi-week studies, prepare single-use aliquots immediately after reconstitution and freeze whatever will not be used within a few weeks. For in vivo protocol design, see our comparison of subcutaneous versus intramuscular administration in research models.
Storage & Stability
The lyophilized powder is stable for up to 24 months at −20°C when kept desiccated and protected from light; brief room-temperature exposure during shipping does not compromise the powder. Once reconstituted, store at 2–8°C and use within 4 weeks, or aliquot and hold at −80°C for up to 6 months. Avoid repeated freeze–thaw cycles, which progressively reduce biological activity.
Our peptide storage guide and guide to spotting degraded peptides cover the warning signs — clumped powder, cloudy solution, or drifting assay results. The peptide half-life chart helps align dosing intervals with the short circulating half-life of mitochondrial-derived peptides.
Certificate of Analysis
Every vial ships with a batch-specific Certificate of Analysis generated by an independent third-party laboratory. The COA reports HPLC purity (≥99%), mass-spectrometry confirmation of the 2174.64 g/mol molecular weight, and lot identification that matches the label on your vial. Confirming the parent mass without satellite peaks is the simplest way to rule out oxidized or truncated variants. If you are new to reading these documents, our guide to reading a peptide COA walks through each section.
Why Researchers Choose PSPeptides
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- Consistent Supply: Laboratories that buy MOTS-C from us on a recurring basis get the same batch-to-batch quality and dependable stock.
MOTS-C Research in Aging and Longevity
One of the most active areas of inquiry is the relationship between this mitochondrial peptide and the aging process. Circulating MOTS-C declines with age in both humans and rodents, mirroring the loss of aerobic capacity and metabolic flexibility seen clinically. That pattern has led several groups to treat the peptide as a systemic readout of mitochondrial health rather than a muscle-only signal.
In aged mice, late-life treatment improved grip strength, running capacity, and metabolic markers in the Reynolds study described above, and Kumagai et al. (2021) reported reduced myostatin and muscle-atrophy signaling. Because these effects did not depend on dietary manipulation, the peptide offers a cleaner experimental variable than caloric-restriction paradigms. Our overview of the best peptides for longevity research places it alongside Epithalon and other candidates in the field.
MOTS-C and Metabolic Disease Research
Type 2 diabetes and obesity remain the most common experimental contexts. The 2015 Cell Metabolism data showed reduced weight gain, lower adiposity, and improved glucose tolerance in high-fat-diet mice, and later studies extended the insulin-sensitizing effect to ovariectomized females and aged animals. Mechanistically, the peptide increases glucose uptake in muscle, improves adipose insulin signaling, and lowers circulating free fatty acids.
For researchers comparing metabolic peptides, our guides to tirzepatide and AOD-9604 provide useful contrasts: those compounds act through incretin receptors or growth-hormone fragments, whereas MOTS-C acts on an intracellular energy-sensing axis. The peptide stacking guide discusses how investigators combine mechanistically distinct peptides within a single protocol.
Purity and Quality Assurance
Purity is non-negotiable in mitochondrial peptide research. Impure preparations containing truncated sequences, oxidized methionine residues, or co-eluting synthesis by-products produce results that fail to replicate across laboratories. Because methionine occupies positions 1 and 6 of the MOTS-C sequence, oxidation is the most common degradation route, and the mass-spectrometry panel on the COA is the place to check for it.
PSPeptides uses an independent laboratory for all testing so there is no conflict of interest in the reported numbers, and the ≥99% specification is held on every lot rather than quoted as a typical value. Our guide to choosing a research peptide supplier explains which documentation to ask for before you buy MOTS-C peptide from any source.
Frequently Asked Questions
What is the molecular weight and sequence of MOTS-C?
The peptide has a molecular weight of 2174.64 g/mol and the 16-residue sequence Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg (MRWQEMGYIFYPRKLR). Mass-spectrometry confirmation of this mass is included on every batch COA, which verifies both identity and the absence of significant degradation.
How does MOTS-C differ from GLP-1 or growth-hormone peptides?
Unlike GLP-1 agonists or GHRH analogs, which act on cell-surface hormone receptors, this mitochondrial peptide works inside the cell through AMPK, the folate–AICAR axis, and nuclear gene regulation. It therefore targets a different layer of metabolic control, which is why it is often studied alongside, rather than instead of, hormonal peptides.
Is MOTS-C related to Humanin?
Both are mitochondrial-derived peptides encoded within mitochondrial rRNA genes, but they are distinct molecules with different sequences and primary functions. Humanin research centers on neuroprotection and anti-apoptotic signaling, whereas MOTS-C research centers on metabolism, exercise physiology, and aging. See our peptide glossary for definitions of related terms.
What purity should I look for when I buy MOTS-C?
For publishable work, ≥99% purity confirmed by HPLC with mass-spectrometry identity verification is the standard. Lower grades introduce contaminant peptides that can confound dose-response data. Every PSPeptides vial meets this threshold with independent documentation.
Should I choose the 10 mg or 50 mg vial?
Choose 10 mg for pilot or short in vitro work and 50 mg for multi-week in vivo studies or any protocol where staying on a single lot matters. Both are identical in purity and are reconstituted the same way.
How quickly will my order ship, and how should I store it on arrival?
Orders placed before 2 PM EST ship the same business day with tracking, and standard shipping is free on every order. Lyophilized peptide tolerates ambient temperatures in transit, so on arrival simply move the vial to a −20°C freezer, keep it in its original packaging away from light, and reconstitute only when you are ready to begin the experiment.
Is it legal to purchase MOTS-C for research?
Research peptides are sold for laboratory use by qualified researchers. Our 2026 guide to research peptide legality covers current regulatory considerations for procurement in the United States and the other countries we ship to.
Related Research Resources
PSPeptides ships to qualified researchers across the United States, with international shipping now available to Canada, the EU, the UK, and Australia. Packages are discreetly labeled with full tracking. If you have questions about reconstitution volumes or experimental design before you buy MOTS-C, our research team is available seven days a week. An intranasal MOTS-C spray is also available for laboratories that prefer a pre-mixed, metered format.
All PSPeptides products are sold exclusively for laboratory and research use. Not intended for human consumption, veterinary use, or food additive purposes.
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