# MOTS-c Research: Mechanism, Studies, and Clinical Status

> MOTS-c mechanism of action, key findings from Lee 2015 (Cell Metabolism), Reynolds 2021 (Nature Communications), aging studies, and comparison with humanin and SHLP2. Cited.

## MOTS-c Mechanism of Action

MOTS-c operates through the folate-AICAR-AMPK axis. The peptide is secreted from mitochondria into the cytoplasm, where it inhibits folate cycling and de novo purine biosynthesis. This inhibition causes AICAR to accumulate, activating AMPK. Elevated AMPK drives increased glucose uptake via GLUT4 translocation in skeletal muscle, enhanced beta-oxidation of fatty acids, and suppression of hepatic lipid accumulation [1][17].

Under metabolic stress, MOTS-c translocates from the cytoplasm to the nucleus within 30 minutes, AMPK-dependently. In the nucleus it physically interacts with NRF2 and upregulates ARE-target genes NQO1 and HO-1 [4].

A 2024 study identified CK2alpha (casein kinase 2 alpha) as a direct molecular binding target. MOTS-c binds CK2alpha at approximately 1 nM affinity in skeletal muscle, activating it and preventing atrophy while enhancing glucose uptake [12].

A separate 2024 study identified TRIM72 (MG53) membrane repair scaffolding as another non-metabolic role [15].

## MOTS-c Benefits: Evidence from the Literature

**Metabolic regulation.** In diet-induced obese mice, MOTS-c at 15 mg/kg/day intraperitoneal reduced body weight gain, improved glucose tolerance, lowered fasting insulin, and decreased hepatic lipid accumulation [1].

**Exercise performance.** Exogenous MOTS-c significantly improved treadmill running capacity and rotarod performance in young, middle-aged, and old mice. Old mice treated with MOTS-c outperformed untreated middle-aged controls [2].

**Muscle atrophy prevention.** At 10 µM in primary human myotubes, MOTS-c completely preserved myotube cross-sectional area against glucocorticoid-induced atrophy [13].

**Cardiac protection.** In a mouse heart-failure model, MOTS-c at 5 mg/kg/day subcutaneous for four weeks attenuated cardiac dysfunction, reduced fibrosis, and activated AMPK in cardiac tissue [10]. A 2025 rat study confirmed MOTS-c restores mitochondrial respiration in the type-2-diabetic heart [11].

**Bone metabolism.** MOTS-c promoted osteoblast collagen production via TGF-beta/SMAD signaling in postmenopausal mouse models [20].

All interventional benefit data are from rodent models. Human interventional data are absent.

## Metabolic Effects: Fat Reduction and Insulin Sensitivity

Lee et al. (Cell Metabolism, 2015) is the foundational metabolic study. MOTS-c at 15 mg/kg/day in diet-induced obese mice reduced adiposity, improved insulin sensitivity, and lowered liver fat via AMPK activation [1].

A 2019 metabolomics study confirmed the mechanism: MOTS-c at 2.5 mg/kg twice daily for three days reduced plasma sphingolipid, monoacylglycerol, and dicarboxylate metabolites [5].

Human observational data: circulating MOTS-c is significantly lower in obese male children and adolescents versus healthy controls (465 vs 584 ng/mL, P<0.001), inversely correlated with BMI, waist circumference, fasting insulin, HOMA-IR, and HbA1c [7][8].

## MOTS-c and Exercise Performance

Reynolds et al. (Nature Communications, 2021) established MOTS-c as an exercise-induced peptide:

1. Exogenous MOTS-c at 5 mg/kg three times per week subcutaneous produced a twofold improvement in treadmill running distance in middle-aged and old mice [2].
2. Human stationary cycling induced an 11.9-fold increase in skeletal muscle MOTS-c expression and a 1.5–1.6-fold rise in circulating MOTS-c, returning to near-baseline within four hours post-exercise [3].
3. Late-life intermittent treatment improved grip strength, stride length, and walking capacity, with a trend toward 6.4% extended median lifespan [2].

## MOTS-c and Aging Biology

Circulating MOTS-c declines with age: plasma levels in 45–55-year-olds are 11% lower than in 18–30-year-olds; in 70–81-year-olds they are 21% lower [6].

In parallel, skeletal muscle MOTS-c expression is approximately 1.5-fold higher in older versus younger men, suggesting compensatory tissue upregulation as systemic levels fall [6].

## MOTS-c vs Humanin and SHLP2

All three are mitochondrial-derived peptides — but the similarities stop at genome origin [18].

- **MOTS-c:** 16 amino acids, encoded by MT-RNR1 (12S rRNA), primary role: metabolic regulation, AMPK activation
- **Humanin:** 21 amino acids, encoded by MT-RNR2 (16S rRNA), primary role: cytoprotection, neuroprotection
- **SHLP2:** 24–38 amino acids, encoded by MT-RNR2 (16S rRNA), primary role: neuroprotection, OXPHOS restoration

MOTS-c is prohibited under WADA S4.4.1. Humanin is not listed on the 2025 WADA prohibited list. SHLPs are not listed.

## Human Clinical Trial Status

No completed Phase 2 or Phase 3 clinical trials for the native MOTS-c sequence have been published as of 2025. Available human data are observational (circulating MOTS-c in aging and obesity cohorts [6][7][8]) and exercise-induced endogenous response studies [3]. CB-4211, a MOTS-c analog for obesity, entered early human trials but Phase 2 results have not been published.

## References

[1] Lee C, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metabolism. 2015;21(3):443-454. DOI: 10.1016/j.cmet.2015.02.009 PMID: 25738459

[2] Reynolds JC, et al. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nature Communications. 2021;12(1):773. DOI: 10.1038/s41467-020-20790-0 PMID: 33473109

[3] Reynolds JC, et al. [Human exercise data.] Nature Communications. 2021;12(1):773. PMID: 33473109

[4] Kim KH, et al. The Mitochondrial-Encoded Peptide MOTS-c Translocates to the Nucleus. Cell Metabolism. 2018;28(3):516-524. DOI: 10.1016/j.cmet.2018.06.008 PMID: 29983246

[5] Kim SJ, et al. The mitochondrial-derived peptide MOTS-c is a regulator of plasma metabolites and enhances insulin sensitivity. Physiological Reports. 2019;7(13):e14171. DOI: 10.14814/phy2.14171 PMID: 31293078

[6] D'Souza RF, et al. Increased expression of MOTS-c in skeletal muscle of healthy aging men. Aging (Albany NY). 2020;12(5):5044-5065. DOI: 10.18632/aging.102944 PMID: 32182209

[7] Du C, et al. Circulating MOTS-c levels are decreased in obese male children and adolescents. Pediatric Diabetes. 2018;19(5):1058-1064. DOI: 10.1111/pedi.12685 PMID: 29691953

[8] Luo YH, et al. Serum MOTS-C Levels are Decreased in Obese Children. Diabetes, Metabolic Syndrome and Obesity. 2023;16:1125-1133. DOI: 10.2147/DMSO.S403934 PMID: 37077579

[9] Zempo H, et al. A pro-diabetogenic mtDNA polymorphism in MOTS-c. Aging (Albany NY). 2021;13(2):1801-1817. DOI: 10.18632/aging.202529 PMID: 33468709

[10] Zhong P, et al. Mitochondrial derived peptide MOTS-c prevents heart failure. JCMM. 2022;26(21):5672-5683. DOI: 10.1111/jcmm.17551 PMID: 36156853

[11] Pham T, et al. MOTS-c restores mitochondrial respiration in type 2 diabetic heart. Front Physiol. 2025;16:1602271. DOI: 10.3389/fphys.2025.1602271 PMID: 40661667

[12] Kumagai H, et al. MOTS-c modulates skeletal muscle function by directly binding and activating CK2. iScience. 2024;27(11):111212. DOI: 10.1016/j.isci.2024.111212 PMID: 39559755

[13] Elhusseiny R, et al. Mitochondrial-derived peptides MOTS-c and humanin attenuate dexamethasone-induced atrophy. Physiological Reports. 2026;14(4):e70791. DOI: 10.14814/phy2.70791 PMID: 41732124

[15] Jia H, et al. Mitochondria-encoded peptide MOTS-c participates in plasma membrane repair via TRIM72. Theranostics. 2024;14(14):5480-5497. DOI: 10.7150/thno.100321 PMID: 39310099

[17] Wan W, et al. Mitochondria-derived peptide MOTS-c: effects and mechanisms. J Transl Med. 2023;21(1):36. DOI: 10.1186/s12967-023-03885-2 PMID: 36670507

[18] Cobb LJ, et al. Naturally occurring mitochondrial-derived peptides are age-dependent regulators. Aging (Albany NY). 2016;8(4):796-809. DOI: 10.18632/aging.100943 PMID: 27070352

[19] Mohtashami Z, et al. MOTS-c in Human Aging and Age-Related Diseases. IJMS. 2022;23(19):11991. DOI: 10.3390/ijms231911991 PMID: 36233287

[20] Mohtashami Z, et al. [Bone metabolism data.] IJMS. 2022;23(19):11991. PMID: 36233287

---

Calibrated from the peer-reviewed record — a machined-instrument digest of the MOTS-c literature, not a clinic, not a vendor, not a prescription.