pe
pep-00003 v1 CC-BY-SA-4.0

MOTS-c: natural mitochondrial peptide tied to metabolism and longevity

A small signaling peptide the body makes from its own mitochondrial DNA; it boosts cellular energy use, rises with exercise, and declines with age, experimental, not yet an approved drug.

statusbioassayed targetLONGEVITY length16 aa refs5
reclassified-feb-2026mitochondrialmdpampkmetabolicfda-not-approvedreference-scaffold
status 2 / 5 · 0 verified on platform
prediction metrics boltz-2 2.2.1
ipTM0.000
pTM0.114
avg pLDDT68.7
ranking score0.572
STRUCTURE · PEP-00003 × LONGEVITY
ranking0.572
?
RECEPTOR UNKNOWN
peptide conformation only · no target structure
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
sequence16 aa
15101516
MRWQEMGYIFYPRKLR
in the news 11 articles
overview readme

What this is

MOTS-c (Mitochondrial Open Reading Frame of the 12S rRNA Type-c) is a 16-amino-acid peptide that the body produces from its own mitochondrial DNA — making it one of a rare class of signals that originates in the cell's energy machinery rather than in the nucleus. It was discovered in 2015 by Pinchas Cohen and Changhan Lee at the USC Leonard Davis School of Gerontology and published in Cell Metabolism (Lee and colleagues 2015). Endogenous MOTS-c levels increase with acute exercise in humans and decline with aging. A mitochondrial DNA polymorphism in the MOTS-c coding region has been associated with type 2 diabetes risk in certain populations, suggesting MOTS-c plays a role in normal human metabolic regulation.

History

MOTS-c was first described in 2015 by Lee and colleagues at the University of Southern California (Cell Metabolism 2015). The conceptual novelty was stark: the peptide is encoded within a small open reading frame embedded inside the mitochondrial 12S ribosomal RNA gene — one of only a handful of peptides whose gene sits within mitochondrial rather than nuclear DNA. Humanin, also characterized by the Cohen lab, was the prototype mitochondria-derived peptide; MOTS-c extended the concept to a metabolically active regulator with exercise-responsive circulating levels. The initial paper showed MOTS-c levels rise after acute exercise in humans and that exogenous administration improved insulin sensitivity and reduced obesity in high-fat-diet mice. Subsequent work extended the biology into muscle, cardiovascular, bone, and aging contexts. A pro-diabetogenic mitochondrial DNA polymorphism in the MOTS-c coding region was later identified (Reynolds and colleagues 2021, Nature Communications). Despite scientific traction, MOTS-c has not entered late-stage clinical development; what is sold under the MOTS-c label is synthetic peptide produced outside the regulated pharmaceutical supply chain, with no FDA-approved therapeutic indication.

What it does

MOTS-c activates AMPK — the cell's core energy-sensing switch — through a cascade that begins in the mitochondria. AMPK activation promotes glucose uptake, fatty acid oxidation, and mitochondrial biogenesis; it is the same pathway engaged by exercise and metformin. In addition to this cytoplasmic role, MOTS-c translocates to the nucleus under metabolic or oxidative stress, where it directly adjusts gene expression linked to antioxidant defense and metabolic adaptation — an unusual retrograde signaling route from organelle to nucleus. In skeletal muscle models, it promotes GLUT4 translocation to the cell surface, improving insulin-stimulated glucose clearance. Animal studies show exogenous MOTS-c reduces fat mass, improves glucose tolerance, and slows age-related physical decline; endogenous circulating MOTS-c levels in humans correlate inversely with insulin resistance, obesity, and cardiovascular risk markers.

Evidence

  • Human: Observational only. Multiple cross-sectional studies link lower circulating MOTS-c to insulin resistance, obesity, and PCOS (Kim and colleagues 2018, Cell Reports; plasma MOTS-c studies 2018). A multicenter cohort study identified endogenous MOTS-c as a mortality predictor in hemodialysis patients. Human exercise studies consistently show acute endurance exercise raises circulating MOTS-c. No controlled interventional trial of exogenous MOTS-c has been completed; a first-in-human trial in insulin resistance was registered in 2025 with no results available at time of writing. CohBar's CB4211 — a MOTS-c analog with modified pharmacokinetics, not MOTS-c itself — completed a Phase 1b study in 20 obese NAFLD patients (25 mg SC daily, 4 weeks) showing reductions in ALT, AST, and glucose versus placebo; Phase 2 never ran after CohBar wound down in 2023. This supports MOTS-c-derived pharmacology in humans but does not constitute evidence for MOTS-c itself.
  • Animal: Extensive. Diet-induced obesity and aging models show AMPK activation, improved insulin sensitivity, reduced fat mass, and prevention of muscle atrophy. Reynolds and colleagues (Nature Communications 2021) demonstrated enhanced physical performance in young, middle-age, and old mice. Cardiac protection and myocardial performance improvement in exercise-trained rats have been reported. Multiple independent research groups have replicated core metabolic findings.
  • In vitro: AMPK activation via AICAR accumulation demonstrated; MOTS-c translocates to the nucleus under oxidative and metabolic stress (MOTS-c nuclear translocation study 2018, Cell Metabolism); GLUT4 upregulation in skeletal muscle cell models; folate-methionine cycle inhibition as the upstream trigger of AICAR accumulation.

Known effects

  • Insulin sensitization / glucose tolerance — Preclinical (animal); supported by original 2015 Cell Metabolism paper and multiple independent replications; human observational correlation only
  • Exercise-responsive circulating levels — Human; established biomarker finding across multiple RCT and observational studies
  • Improved physical performance in aging — Animal (Reynolds and colleagues 2021, Nature Communications); young, middle-age, and old mice; no human interventional data
  • Muscle atrophy reduction — Animal; myostatin and atrophy signaling reduced in preclinical models
  • Cardiac/myocardial effects — Animal; preclinical models of heart failure and exercise training
  • Mortality correlation in dialysis patients — Human observational; multicenter cohort study; endogenous levels only
  • Endocrine marker changes with cancer radiation — Human observational; serum MOTS-c levels measured in patients with lung and breast cancer receiving radiation therapy

Safety signals

No clinical safety trial for MOTS-c itself has been completed. All available human safety data come from the CB4211 analog program: Phase 1a in 65 healthy volunteers identified persistent injection-site reactions as the primary adverse event; no serious adverse events were reported. For MOTS-c itself, safety in humans is entirely uncharacterized.

Theoretical concern — additive effects with glucose-lowering agents: MOTS-c activates AMPK and improves insulin-stimulated glucose uptake; source literature describes potential additive hypoglycemia risk with insulin, sulfonylureas, meglitinides, and metformin. No controlled interaction data in humans exists.

Research-chemical quality: source literature notes synthetic MOTS-c sold through research-chemical channels varies in purity, peptide identity, and endotoxin contamination; 16-residue synthesis complexity increases contamination risk relative to shorter peptides. Chronic exogenous AMPK activation has not been studied at any dose or duration in humans.

Regulatory status

  • US (FDA): Not approved. Removed from the 503A Category 2 compounding nomination list (April 2026; nomination withdrawn). FDA intended to consult PCAC in July 2026 regarding MOTS-c acetate and free-base forms — outcome not yet reflected in this card. No compounding authorization; no prescription pathway. Sales occur through research-chemical suppliers.
  • EU (EMA): No marketing authorization.
  • UK (MHRA): No license.
  • Canada: No approval; investigational only.
  • Australia (TGA): No approval; general enforcement action against unapproved peptide sales applies.
  • WADA: Prohibited under S0 (non-approved substances for human therapeutic use) per available sources; current list status not independently refreshed for this card.

Mechanism

MOTS-c (sequence MRWQEMGYIFYPRKLR; 16 residues; endogenously encoded in the mitochondrial 12S rRNA gene) activates AMPK through inhibition of the folate-methionine cycle, leading to accumulation of AICAR — an endogenous AMPK activator first shown in the original 2015 Cell Metabolism paper. AMPK activation drives glucose uptake, fatty acid oxidation, and mitochondrial biogenesis. MOTS-c also translocates to the nucleus under metabolic or oxidative stress to regulate gene expression related to antioxidant response and metabolic adaptation — a mechanism characterized in cell and animal models (Kim and colleagues 2018, Cell Metabolism). GLUT4 translocation to the plasma membrane in skeletal muscle improves insulin-stimulated glucose clearance. In rodent exercise models, MOTS-c interacts synergistically with physical activity to regulate PGC-1α expression and attenuate insulin resistance via AMPK signaling (Zhu and colleagues 2021, Biochimica et Biophysica Acta). The nuclear translocation mechanism depends on intracellular MOTS-c; whether subcutaneously injected synthetic MOTS-c reaches the relevant intracellular compartments to reproduce this pathway is unresolved.

Open questions

  • Human pharmacokinetics — absorption, distribution, half-life, and tissue uptake of exogenous MOTS-c have not been characterized in humans at any dose or route
  • Nuclear translocation recapitulation — the mitochondria-to-nucleus translocation that drives much of the interesting biology may not be recapitulated by subcutaneous dosing; whether injected synthetic MOTS-c reaches the intracellular compartments relevant to its mechanism is unresolved
  • Translation of observational signals — human studies link endogenous MOTS-c levels to metabolic health, but whether raising levels via exogenous dosing reproduces the protective associations is untested
  • CB4211 vs MOTS-c equivalence — CB4211 has modified pharmacokinetics; its Phase 1b signal may or may not generalize to the parent molecule
  • Long-term safety — chronic exogenous AMPK activation has not been studied in humans at any dose or duration
  • Dose-ranging — no controlled trial has identified minimum effective or maximum tolerated human doses

Myths and misconceptions

  • "MOTS-c can replace exercise." Exercise activates hundreds of adaptive pathways across cardiovascular, musculoskeletal, neural, and metabolic systems. MOTS-c engages a subset of metabolic signaling that overlaps with exercise — primarily AMPK — but does not reproduce the full physiological response (Lee and colleagues 2015).
  • "Because MOTS-c is naturally produced in the body, exogenous MOTS-c is automatically safe." Endogenous MOTS-c is regulated by mitochondrial gene expression and metabolic state. Subcutaneously injected synthetic MOTS-c bypasses that regulation entirely, and its safety profile in humans has not been characterized at any dose.
  • "MOTS-c is FDA-approved or in late-stage clinical development." MOTS-c is not FDA-approved for any indication and has not entered late-stage human trials. The published human evidence is largely observational — measuring endogenous MOTS-c levels in patient populations — not interventional.

Related peptides

  • Humanin — the prototype mitochondria-derived peptide (MDP) from the same research lineage; acts through different receptors with neuroprotective emphasis (card not yet linked)
Hypotheses6 directions▾ collapse

Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.

openupdated 2026-06-05

Could a mitochondrial peptide keep muscles strong during long-term steroid treatment?

If true, patients on prednisone or similar drugs for arthritis, asthma, or autoimmune disease could keep their muscle strength. That would mean fewer falls, better mobility, and less disability during treatment.

The hypothesis
MOTS-c or a stabilized analog could reverse glucocorticoid-induced muscle atrophy by restoring AMPK-PGC-1alpha axis activity without interfering with the anti-inflammatory actions of glucocorticoids
Why it’s plausible
Glucocorticoids are widely used anti-inflammatory drugs but cause debilitating muscle wasting via suppression of the AMPK-PGC-1alpha pathway. MOTS-c is exercise-mimetic and activates AMPK in skeletal muscle. Because MOTS-c acts downstream or parallel to glucocorticoid receptors rather than antagonizing them, it might preserve muscle mass without blunting immunosuppression. This is a distinct therapeutic angle from generic metabolic enhancement.
Why it matters
There is no approved therapy that prevents glucocorticoid-induced myopathy while preserving anti-inflammatory benefit. If MOTS-c can uncouple these effects, it would fill a major unmet need in chronic inflammatory disease management.
Plausibility.50
Novelty.70
Impact.75
Basis · grounding2 papers · 1 computed/note
[1]
paper
MOTS-c promotes metabolic adaptations in skeletal muscle, including exercise-mimetic AMPK activation
doi: 10.1038/s41467-020-20790-0
[2]
noteMOTS-c levels rise with acute exercise and decline with aging, positioning it as an exercise mimetic
[3]
paper
Original study showing improved metabolic parameters in high-fat-diet mice
doi: 10.1016/j.cmet.2015.02.009
openupdated 2026-06-05

Could attaching a fat molecule to MOTS-c make it last long enough for weekly shots?

If true, patients with diabetes or age-related metabolic decline could take a simple weekly injection instead of daily pills. That would mean better adherence, lower cost, and a more practical path from lab to pharmacy.

The hypothesis
Conjugating MOTS-c to a fatty-acid chain at the N-terminal methionine will extend its plasma half-life while preserving or enhancing membrane insertion, yielding a long-acting metabolic modulator suitable for weekly dosing
Why it’s plausible
MOTS-c is only 16 amino acids and likely susceptible to rapid renal filtration and proteolysis. N-terminal fatty acylation is a proven half-life extension strategy for small peptides (e.g., liraglutide, semaglutide). Because the hypothesized membrane-recognition motif includes the N-terminal Met-Trp pair, fatty-acid conjugation at this position could synergize with the native mechanism by deepening membrane insertion, rather than merely acting as a pharmacokinetic appendage.
Why it matters
A weekly-dose MOTS-c analog would transform its developability from an academic tool into a practical therapeutic for metabolic disease and aging. The synergy between half-life extension and mechanism would be a design advantage over generic PEGylation or fusion approaches.
Plausibility.60
Novelty.55
Impact.70
Basis · grounding3 computed/notes
[1]
sequenceN-terminal methionine at position 1 provides a site for acylation without disrupting the C-terminal functional tail
[2]
structureMonomeric, unstructured peptide (pLDDT=68.7) suggests that N-terminal modification is unlikely to disrupt a folded binding site
[3]
noteMOTS-c declines with aging and has therapeutic potential in metabolic disease, but peptide stability and dosing frequency are practical barriers
openupdated 2026-06-05

Could a tiny peptide boost energy balance just by touching the cell surface?

If true, we could redesign MOTS-c to target specific organs by changing its surface charge. That would mean safer, more precise metabolic drugs for people with diabetes or age-related weight gain.

The hypothesis
The C-terminal basic tail (PRKLR) of MOTS-c mediates AMPK activation through direct electrostatic interaction with negatively charged phospholipid headgroups at the plasma membrane rather than through a classical protein receptor
Why it’s plausible
MOTS-c is only 16 aa with no evident globular binding domain (pLDDT=68.7 monomer, no interface prediction). Yet it robustly activates AMPK in muscle and improves insulin sensitivity. Short basic peptides often dock to membrane phosphoinositides before engaging downstream kinases. The C-terminal PRKLR motif is strongly basic (3/5 residues: R, K, R) and conserved, suggesting membrane recruitment as a mechanistic step prior to AMPK engagement.
Why it matters
If membrane docking is the initiating event, then MOTS-c analogs could be engineered by altering the basic tail charge pattern to tune tissue selectivity (e.g., muscle vs. liver) without changing the core sequence. It would also explain why MOTS-c acts rapidly and systemically despite lacking a known receptor.
Plausibility.55
Novelty.60
Impact.55
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceC-terminal residues 12-16 are PRKLR, containing three basic residues (Pro-Arg-Lys-Leu-Arg) in a 5-residue stretch
[2]
structureboltz-2 monomer pLDDT=68.7, ipTM=None, no predicted binding interface, consistent with non-globular membrane-associated mechanism
[3]
paper
Original discovery paper showing MOTS-c improves insulin sensitivity and activates AMPK in mice
doi: 10.1016/j.cmet.2015.02.009
openupdated 2026-06-05

Could the first two building blocks of MOTS-c act like a tiny anchor on cell membranes?

If true, drug designers could swap those first two blocks to make MOTS-c last longer or hit different tissues. People with insulin resistance could get more effective, longer-lasting treatments.

The hypothesis
The N-terminal methionine and adjacent tryptophan (positions 1-2, MW) form a transient membrane-insertion motif that anchors MOTS-c at the membrane before the C-terminal tail engages AMPK
Why it’s plausible
Position 1 is methionine and position 2 is tryptophan. Tryptophan has a strong preference for the membrane interface region due to its amphipathic indole side chain, and N-terminal methionine can initiate membrane association in short peptides. This would create a bipartite membrane-recognition module: N-terminal interfacial anchoring plus C-terminal electrostatic docking. Such bipartite motifs are common in antimicrobial and cell-penetrating peptides but have not been described for MOTS-c.
Why it matters
Identifying a bipartite membrane-recognition motif would provide a rational basis for structure-activity studies: replacing Trp-2 with other aromatic residues could modulate membrane dwell time and thus signaling potency. It would also explain why MOTS-c is active at nanomolar concentrations despite its small size.
Plausibility.50
Novelty.65
Impact.50
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceN-terminus is Met-Trp-Gln-Glu (MWQE); Trp at position 2 is a known membrane-interface residue
[2]
structureNo stable globular structure predicted, consistent with unstructured peptide that interacts with membranes
[3]
paper
MOTS-c promotes metabolic adaptations in skeletal muscle, implying efficient cellular uptake or surface engagement
doi: 10.1038/s41467-020-20790-0
openupdated 2026-06-05

Could a tiny genetic typo in MOTS-c rob some people of their natural metabolic protection?

If true, doctors could test for this variant and give MOTS-c replacement to those who need it most. That would mean earlier, personalized prevention of type 2 diabetes in high-risk families.

The hypothesis
The mitochondrial DNA polymorphism linked to type 2 diabetes risk alters MOTS-c primary sequence at a position critical for membrane docking, producing a loss-of-function variant that fails to activate AMPK efficiently
Why it’s plausible
A mitochondrial DNA polymorphism in the MOTS-c coding region is associated with type 2 diabetes risk. If this polymorphism changes an amino acid in the N-terminal membrane-interfacial region or C-terminal basic tail, it could weaken membrane association and downstream AMPK signaling. This would reframe the polymorphism from a statistical risk marker to a functional variant with a mechanistic explanation.
Why it matters
Linking a specific coding variant to impaired membrane docking would enable genotype-guided screening: individuals carrying the variant might benefit most from MOTS-c replacement therapy. It would also guide engineering of resistant analogs that bypass the affected position.
Plausibility.40
Novelty.50
Impact.65
Basis · grounding3 computed/notes
[1]
noteA mitochondrial DNA polymorphism in the MOTS-c coding region has been associated with type 2 diabetes risk in certain populations
[2]
sequenceFull sequence MRWQEMGYIFYPRKLR; any coding polymorphism altering positions 1-2 (membrane interface) or 12-16 (basic tail) would plausibly disrupt function
[3]
structureNo stable structure predicted; function likely depends on specific sequence features rather than folded architecture
openupdated 2026-06-05

Could a tiny metabolic peptide help people stay strong enough to finish cancer immunotherapy?

If true, more patients could complete their full course of immunotherapy and respond better. That would mean longer survival and fewer treatment stops due to weakness or weight loss.

The hypothesis
MOTS-c could be repurposed as an adjuvant to immune checkpoint inhibitors to counteract the therapy-induced hypermetabolic state and cachexia that limit durable responses
Why it’s plausible
Immune checkpoint blockade can trigger systemic inflammation and cancer cachexia, driven in part by dysregulated host metabolism. MOTS-c improves insulin sensitivity and reduces adiposity in obese mice. If similar metabolic rebalancing occurs in the context of anti-tumor immunity, MOTS-c might sustain lean mass and energy availability, prolonging T-cell function and treatment tolerance. This repurposes a metabolic peptide into an immuno-oncology supportive agent.
Why it matters
Checkpoint inhibitor durability is often limited by patient frailty and cachexia. A metabolic adjuvant that is already endogenous and well-tolerated could extend the therapeutic window of billion-dollar immunotherapies.
Plausibility.35
Novelty.70
Impact.55
Basis · grounding2 papers · 1 computed/note
[1]
paper
MOTS-c administration improved insulin sensitivity and reduced obesity in high-fat-diet mice
doi: 10.1016/j.cmet.2015.02.009
[2]
noteMOTS-c is endogenous, exercise-responsive, and declines with aging, suggesting favorable safety profile
[3]
paper
MOTS-c drives metabolic adaptations in skeletal muscle relevant to whole-body energy balance
doi: 10.1038/s41467-020-20790-0
details expand to inspect
full evidence table1 metrics
metricvaluetool
ranking score 0.5723018646240234 boltz-2
3-letter notation
Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg
recipeboltz-2 2.2.1
parametervalue
modelboltz-2 2.2.1
weights
hardwarevast_v100_32gb
mlx version
python
random seed1
msa strategynone_monomer
runtime
predicted by
predicted at2026-05-23
citationbibtex
peptidemodel (2026). MOTS-c: natural mitochondrial peptide tied to metabolism and longevity (pep-00003, v1). PeptideModel. https://peptidemodel.com/card/pep-00003
@peptide{pep00003,
  sequence = {MRWQEMGYIFYPRKLR},
  target   = {longevity},
  author   = {peptidemodel},
  year     = {2026},
  status   = {bioassayed}
}
clinical trials 7 on ct.gov · 2 on EUCTR · checked 2026-05-09
ct.gov trials 7
EUCTR 2
PubMed RCT 3
by phase
1phase 26no phase
by status
1completed4recruiting1active1unknown
references 5 papers
discussion no comments
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