# MOTS-c

Rating: Early — Mostly animal or cell studies; few or uncontrolled human data
Type: Compound
Updated: 2026-10-14
Canonical: https://heretic.bio/articles/mots-c-mitochondrial-open-reading-frame-of-12s-rrna-type-c.html

> MOTS-c is a 16-amino-acid peptide encoded by mitochondrial DNA that acts like an exercise signal, activating AMPK and improving glucose handling in rodents. Human evidence is thin: the only completed trial tested an analog (CB4211) in a Phase 1 study, where liver enzymes improved but the liver-fat imaging endpoint did not beat placebo. A Phase 2 trial of native MOTS-c in prediabetes started recruiting in 2026. Everything else is rodent data and observational correlations.

> **Aliases:** Mitochondrial ORF of the 12S rRNA Type-C, Mitochondrial-derived peptide MOTS-c **Sequence:** MRWQEMRIFYLRKLF (16 amino acids) — encoded by mitochondrial 12S rRNA gene **Molecular Weight:** ~2.1 kDa **Origin:** Mitochondrial-derived peptide (MDP) — encoded by mitochondrial DNA, translated in cytoplasm

## Overview

MOTS-c is a **mitochondrial-derived peptide** of 16 amino acids encoded by the mitochondrial 12S rRNA gene — one of a small family of mtDNA-encoded signaling microproteins (Humanin, SHLP1–6, SHMOOSE). Discovered in 2015 in the Pinchas Cohen / Changhan Lee labs at USC, it established the concept of a mitochondrial genome-encoded signal that regulates **nuclear gene expression** and systemic metabolism.

Functionally it behaves as an **"exercise mimetic"** : skeletal muscle MOTS-c rises ~12-fold after exercise, and treatment recapitulates exercise-like metabolic adaptations (AMPK activation, improved glucose handling) in rodents.

**Evidence Level (2026):** Moderate — strong preclinical data, human observational correlations, one completed Phase 1a/1b trial of an _analog_ (CB4211), and — as of February 2026 — a **first Phase 2 trial of native MOTS-c itself in prediabetes, recruiting** ([NCT07505745](https://clinicaltrials.gov/study/NCT07505745)). The July 23-24 2026 PCAC meeting produced an FDA briefing that **proposes against placing MOTS-c (free base) or MOTS-c acetate on the 503A Bulks List** for obesity/osteoporosis — see [FDA Peptide Reclassification 2026 — Regulatory Intelligence](fda-peptide-reclassification-2026.html) for the compounding-pharmacy context.

## Mechanism of Action

### Unique Biology

  * **Translation:** in the **cytosol** (not mitochondria) — the polyadenylated 12S rRNA transcript is exported because sORF uses mitochondrial-specific codons
  * **Trafficking:** resting state — mitochondrial; under **metabolic stress** — translocates to the **nucleus** in an AMPK-dependent manner
  * **Nuclear action:** binds ARE-regulated transcription factors → upregulates antioxidant/stress-response genes (NRF2 axis)
  * **Conservation:** first 11 residues conserved across 14 mammalian species



### Key Pathways

  1. **AMPK activation** → enhanced glucose uptake, insulin sensitivity, folate-cycle inhibition → AICAR-like metabolic stress response
  2. **Akt** → positive feedback in skeletal muscle
  3. **NRF2** → mitochondrial protective gene expression
  4. **MAPK inhibition** (ERK/JNK/p38) → anti-inflammatory
  5. **TGF-β pathway inhibition** — reported in ovariectomy-model bone loss (PMID [26861024](https://pubmed.ncbi.nlm.nih.gov/26861024/))



### Exercise Response (Human Data — Reynolds 2021, Nat Commun, [PMC8228264](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8228264/))

Tissue | Change | Timecourse  
---|---|---  
Skeletal muscle (endogenous) | **11.9-fold increase** post-exercise | Elevated ≥4 h  
Plasma | 1.6-fold during, 1.5-fold after exercise | Back to baseline by ~4 h  
  
## Clinical Evidence

### Human Interventional Data — NEW (2021–2026)

**CB4211 (synthetic MOTS-c analog, CohBar) — the only completed interventional human data** \- **[NCT03998514](https://clinicaltrials.gov/study/NCT03998514)** (Phase 1a/1b, completed): ~88 subjects in ascending-dose Ph1a in healthy volunteers; Ph1b in obese NAFLD subjects — 25 mg SC daily × 28 days (n=11) vs placebo (n=9) \- **Safety:** primary endpoint met; no SAEs; injection-site reactions common (trial paused 2018 to amend protocol after persistent painless injection-site nodules) \- **Biomarkers:** ALT **−21%** (placebo +4%), AST **−28%** (placebo −11%), glucose −6% vs placebo — all p<0.05 (topline, Aug 2021 press release; Loomba quote) \- **Caveat:** primary imaging endpoint (MRI-PDFF liver fat) **−5.03% vs −4.88% placebo — NOT separated from placebo**. Biomarkers moved; the disease-relevant measure did not. Program **discontinued before Phase 2** when CohBar hit financial trouble (assets later acquired by Molexus, 2024) — treat the topline "positive" framing with skepticism. \- Press-release data only; never published in a peer-reviewed journal.

**Native MOTS-c Phase 2 (first ever) —[NCT07505745](https://clinicaltrials.gov/study/NCT07505745)** \- **"MOTS-c for Improving Insulin Sensitivity in Adults With Prediabetes and Overweight/Obesity"** \- Phase 2, randomized, **n=120 estimated** , **started 2026-02-02, recruiting** , primary completion Feb 2027 \- **Primary endpoints:** change in OGTT-derived insulin sensitivity (Matsuda Index); TEAE incidence \- Secondary: HbA1c, fasting glucose, 2-h OGTT glucose \- This is the first randomized trial of the native peptide in a metabolic indication — a genuine inflection point for the evidence base. Results expected ~2027.

### Human Observational Data

  * **Prediabetes/diabetes correlation:** plasma MOTS-c inversely associated with fasting insulin, HbA1c, BMI (meta-analysis: _Diabetology & Metabolic Syndrome_ 16:197, 2024; PROSPERO CRD42021248167)
  * **Obese children (5–14 y):** ~20% lower MOTS-c vs lean controls
  * **Aging:** young adults ~11% higher than middle-aged, ~21% higher than elderly
  * **Exceptional longevity:** MOTS-c m.1382A>C polymorphism enriched in Japanese centenarians (Fuku 2015–2016, _Aging Cell_); generalizability to other populations unclear



### Key Preclinical Studies (2025 additions)

  * **Diabetes prevention (Kong et al.,_Exp Mol Med_ 57:1861–1877, 2025, open access):** MOTS-c reduced pancreatic islet/β-cell senescence in three mouse models; suppressed Cdkn1a, Cdkn2a, Cxcl10, Il-1b; human islet data included
  * **Diabetic heart (Pham et al.,_Front Physiol_ 16:1602271, 2025):** restored mitochondrial respiration/ATP and reduced ROS in type-2-diabetic rat myocardium — perfused-heart model
  * **Sepsis brain injury (Bai et al., 2025):** protection against LPS-induced sepsis-associated brain injury
  * **Insulin sensitivity rescue:** 7 days of MOTS-c restored old-mouse insulin sensitivity to young-mouse levels
  * **HFD protection:** prevents weight gain/hyperinsulinemia on high-fat diet without effect on chow-fed mice



### Key Preclinical Studies (2026 additions)

  * **Skeletal-muscle bioenergetics (Gudiksen A et al.,_Free Radic Biol Med_ 246:682–696, Jan 2026, PMID [41520850](https://pubmed.ncbi.nlm.nih.gov/41520850/)):** MOTS-c improves **intrinsic** muscle mitochondrial bioenergetic health and efficiency in a **PGC-1α/AMPK-dependent** manner (mouse model, University of Copenhagen, Novo Nordisk Foundation–funded). Mechanism-level confirmation that the exercise-mimetic effect is _intrinsic to muscle mitochondria_ , not merely a systemic AMPK read-out.
  * **Bone health (Qin Z et al.,_Cell Mol Life Sci_ 2025, doi [10.1007/s00018-025-05802-w](https://doi.org/10.1007/s00018-025-05802-w)):** review of mitochondrial quality-control in bone; cites MOTS-c for PGC-1α induction in primary osteoblasts and **osteoblast-senescence suppression** that promotes bone healing in osteoporotic mice — consistent with the AMPK–RANKL axis originally reported by Hu & Chen 2018 (PMID [30387425](https://pubmed.ncbi.nlm.nih.gov/30387425/)) and the OVX model.
  * **Russian-language review (Bobylev AG, Nekrasov PV,_Human Physiology_ 52(2):280, 2026):** "Mitochondrial Peptide MOTS-c: Regulation of Metabolism and Prospects for Clinical and Sports Medicine Applications" — independent clinical/sports-medicine synthesis (no new primary data).



### Delivery / Probiotic Engineering

  * No established clinical delivery route beyond SC injection; USC group proposed synthetic-biology MOTS-c expression in probiotics (_Lactobacillus_ , _E. coli_ Nissle 1917)



## Primary Uses & Applications

Application | Evidence Level | Notes  
---|---|---  
**Insulin sensitivity / prediabetes** | Phase 2 recruiting | [NCT07505745](https://clinicaltrials.gov/study/NCT07505745); first native-peptide RCT  
**NAFLD/NASH** | Ph1b analog data (mixed) | CB4211 enzymes↓ but MRI-PDFF = placebo  
**Metabolic syndrome / obesity** | Strong preclinical | HFD protection in mice  
**Diabetes prevention** | Preclinical (strong, 2025) | Islet senescence prevention (Exp Mol Med)  
**Anti-aging / longevity** | Epidemiological | Age-decline + centenarian polymorphism  
**Cardiovascular** | Preclinical | Diabetic-heart respiration rescue (2025)  
**Exercise performance** | Human correlative only | Endogenous rise with exercise; no exogenous RCT  
  
## Doses in studies

> ⚠️ **Disclaimer:** No approved human dosing exists. The only randomized human dosing on record is CB4211 25 mg SC daily × 28 days (analog, Phase 1b). Gray-market protocols are extrapolations.

Purpose | Notes  
---|---  
Phase 1b (CB4211 analog) | Only RCT-grade human dosing  
[NCT07505745](https://clinicaltrials.gov/study/NCT07505745) (native) | Await registration details  
Gray-market "metabolic support" | Unvalidated extrapolation  
Gray-market "anti-aging" | Unvalidated extrapolation  
  
  * No published human pharmacokinetics for native MOTS-c



## Safety Profile

Aspect | Assessment  
---|---  
**Human safety** | CB4211 Ph1a/1b: no SAEs; injection-site nodules/reactions most common AE  
**Animal safety** | Well-tolerated across rodent studies  
**Hepatotoxicity** | None observed; avoids the lactic-acidosis/hepatic issues of metformin/AICAR comparators  
**Long-term human safety** | Not established  
**Drug interactions** | Not characterized  
**Regulatory** | Not FDA-approved; see [FDA Peptide Reclassification 2026 — Regulatory Intelligence](fda-peptide-reclassification-2026.html) for the 503A/Category 2 landscape  
  
## Source & Origin

  * **Discovered:** 2015, Cohen/Lee laboratories, USC (Lee C et al., _Cell Metab_ 21:443–454)
  * **Encoding:** mitochondrial 12S rRNA gene (mtDNA), sORF, cytosolic translation
  * **Family:** MDPs — Humanin, SHLP1–6, SHMOOSE, MOTS-c
  * **Commercial lineage:** CohBar (Cohen co-founded) → CB4211 → program dropped → assets to Molexus (2024)



## Regulatory Status — PCAC July 2026 Update

The July 23-24 2026 meeting of the FDA Pharmacy Compounding Advisory Committee (PCAC) included **MOTS-c (free base) and MOTS-c acetate** as a single nominated bulk drug substance (BDS) pair. The nomination was originally submitted by Wells Pharmacy Network (docket FDA-2015-N-3534-0293) and later **withdrawn** (FDA-2015-N-3534-0484), so FDA evaluated the substances at its own initiative. Federal Register notice 91 FR 20465 (April 16 2026, FR Doc. 2026-07361, Docket FDA-2025-N-6895); briefing documents released June 29 2026 (fda.gov/media/193347).

**FDA staff position:** Proposes **against** placing MOTS-c (free base) or MOTS-c acetate on the 503A Bulks List.

**FDA evaluation framework (503A criteria) — where MOTS-c landed:** | Criterion | FDA finding | |---|---| | Physicochemical characterization | **Not well characterized.** Nomenclature inconsistency (free base vs acetate), no impurities/aggregates/endotoxin data in published literature, no Certificate of Analysis in the nomination, missing water-solubility data | | Historical compounding use | **Unknown / not characterized** | | Effectiveness evidence | **No clinical studies in humans** for any proposed use | | Safety evidence | **No nonclinical data to inform safety** for the potential clinical uses; no human clinical studies; FDA notes it lacks the information needed to assess immunogenicity risk for a 16-aa peptide |

**Uses FDA evaluated:** Obesity and osteoporosis (the two proposed indications for which the nomination contained enough information to review). Other proposed uses — vascular calcification, muscle/fat metabolism, longevity, insulin resistance — were **not** evaluated because the nomination did not include sufficient supporting information and FDA did not identify clinical studies for them.

**Specifics that distinguish this file:** \- MOTS-c appears as a **prohibited substance in Global Drug Reference Online** (under the 2024 WADA Prohibited List, "hormone and metabolic modulators" category) — a compounding decision would not change anti-doping status. Same situation as [TB-500 (Thymosin Beta-4)](tb-500-thymosin-beta-4.html). \- FDA's own internet search identified a **holistic clinic advertising compounded MOTS-c** and a **wellness clinic promoting an IV MOTS-c cocktail** without disclosing co-ingredients — signals an active gray-market footprint that the briefing document was specifically built to address. \- Nominated uses (longevity, exercise-mimetic) are popular talking points but **not what FDA evaluated** — the agency reviews a BDS in the context of the use proposed.

**Status as of Sept 2026:** FDA's July 23-24 2026 recommendation is a staff position; the agency will issue a final determination after considering committee input and finalizing reviews. A "no" recommendation at PCAC does not mean MOTS-c was found dangerous — the briefing documents almost exclusively cite **missing information** , not positive harm findings. Reporting that framing either way ("FDA says dangerous" / "FDA found no safety problems") is inaccurate.

## Sources

1. ClinicalTrials.gov NCT07505745 : MOTS-c for Improving Insulin Sensitivity in Adults With Prediabetes and Overweight/Obesity (Phase 2, recruiting, started 2026-02-02). (NCT07505745)
2. PubMed 26861024 (PubMed 26861024)
3. Reynolds JC, Lai RW, Woodhead JST et al. (2021). "MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis." Nat Commun 12:470. PMC8228264 (PMC8228264)
4. CohBar Inc. (2021). Phase 1a/1b topline results, CB4211 in NASH/obesity ( NCT03998514 ). GlobeNewswire, Aug 10 2021. Press release — peer-reviewed publication absent. (NCT03998514)
5. Gudiksen A, Hansen CC, van der Stede T et al. (2026). "MOTS-c improves intrinsic muscle mitochondrial bioenergetic health and efficiency in a PGC-1α/AMPK-dependent manner." Free Radic Biol Med 246:682–696. PMID 41520850 . Direct mechanism confirmation in skeletal muscle. (PubMed 41520850)
6. Qin Z et al. (2025). Mitochondrial quality-control in bone. Cell Mol Life Sci . doi 10.1007/s00018-025-05802-w . Reviews MOTS-c osteoblast-senescence suppression. (DOI 10.1007/s00018-025-05802-w)
7. Hu B, Chen W (2018). "MOTS-c improves osteoporosis by promoting osteogenic differentiation of bone marrow mesenchymal stem cells via TGF-β/Smad pathway." Eur Rev Med Pharmacol Sci 22(21):7156–7163. PMID 30387425 . (PubMed 30387425)
8. Lee C, Zeng J, Drew BG et al. (2015). "The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance." Cell Metab 21:443–454. PMID 25801541 (PubMed 25801541)
9. Zheng Y, Wei Z, Wang T (2023). "MOTS-c: a promising mitochondrial-derived peptide for therapeutic exploitation." Front Endocrinol . PMC9905433 (PMC9905433)
10. Wei M et al. (2020). "Mitochondrial-derived peptide MOTS-c attenuates vascular calcification and secondary myocardial remodeling via AMPK signaling." Cardiorenal Med 10(1):42–50. PMID 31694019 . (PubMed 31694019)