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PrecisePep/Peptide Library/MOTS-c

Mitochondrial & Bioenergetic

MOTS-c

Mitochondrial ORF of the 12S rRNA type-c · mitochondrial-derived peptide (MDP)

A 16-residue peptide encoded in mitochondrial DNA that travels to the nucleus under metabolic stress and rewrites the transcriptional response — an exercise-mimetic signalling molecule, not a nutrient.

AMPKInsulin sensitivityExercise mimeticMitochondrial DNARetrograde signallingPCOS interest

00 Overview

MOTS-c overturned an assumption about how mitochondria communicate. Mitochondrial DNA was understood to encode thirteen proteins, all components of the respiratory chain. Lee and colleagues reported in 2015 that a short open reading frame in the 12S rRNA region encodes a 16-amino-acid peptide that leaves the mitochondrion entirely, enters the nucleus under metabolic stress, and regulates nuclear gene expression.[1] That is retrograde signalling — the organelle instructing the cell.

Functionally, MOTS-c targets the folate–purine–AICAR pathway, activating AMPK. AMPK is the cell's energy sensor: activating it shifts metabolism toward glucose uptake, fatty acid oxidation and mitochondrial biogenesis, and away from storage. This is the same node that metformin and exercise act on, which is why MOTS-c is described as an exercise mimetic.[1][2]

The pre-clinical work is strong: MOTS-c prevented diet-induced obesity and insulin resistance in mice, improved physical capacity in aged animals, and its endogenous levels decline with age.[1][3] Human data is another matter — there is observational work relating circulating MOTS-c to metabolic status and exercise, but no controlled trial of administered MOTS-c in humans.

// Mechanism of action

AMPK activation via the folate–purine–AICAR pathway. MOTS-c inhibits the folate cycle, causing accumulation of AICAR — an endogenous AMPK activator. AMPK activation is the central mechanism: it drives GLUT4-mediated glucose uptake, fatty acid oxidation, mitochondrial biogenesis and autophagy, while suppressing lipogenesis and protein synthesis.

Nuclear translocation and transcriptional regulation. Under metabolic stress MOTS-c moves to the nucleus and regulates a stress-response gene programme, including antioxidant response element-driven transcription. This is the retrograde signalling that makes it categorically different from a mitochondrial nutrient or a structural stabiliser.

Improved insulin sensitivity. Downstream of AMPK — increased skeletal muscle glucose uptake independent of insulin, which is why it is discussed alongside metformin.

Exercise-related biology. Circulating MOTS-c rises with acute exercise and skeletal muscle MOTS-c increases in response to training, positioning it as part of the endogenous exercise response rather than an external analogue of it.[2]

Age-related decline. Endogenous MOTS-c levels fall with age — the observation on which most of the longevity reasoning rests.

01 Reported benefits

Effects that have been reported. A study-tier entry means a result was published — not that the effect is established, reproducible, or transferable from a rodent to a person.

Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.

Prevention of diet-induced obesity and insulin resistance [1]

The foundational finding: MOTS-c administration prevented diet-induced obesity and insulin resistance in mice, with increased glucose uptake and improved metabolic homeostasis.

Rodent · in vivo

AMPK activation via the folate–purine–AICAR axis [1]

Mechanistically characterised: MOTS-c targets the folate cycle, driving AICAR accumulation and AMPK activation — a defined molecular pathway rather than a general effect.

In vitro + rodent

Regulation of plasma metabolites and enhanced insulin sensitivity [4]

Metabolomic work confirmed MOTS-c as a regulator of circulating metabolites with insulin-sensitising effect.

Rodent + metabolomics

Improved physical capacity in aged animals [3]

Reported improvements in exercise capacity and muscle function in aged mice, with the effect framed as restoration of a declining endogenous signal.

Rodent · in vivo

Exercise-responsive endogenous regulation [2]

Circulating and skeletal-muscle MOTS-c increase with acute exercise and training in humans — observational human evidence that the peptide is part of the physiological exercise response.

Human observational

Prevention of metabolic disorder across models [5]

Review-level synthesis reports consistent metabolic protection across multiple experimental models.

Review

02 Adverse effects & risks

Adverse effects, contraindications and unknowns. The grey-market tier is where under-reporting is worst: uncontrolled use produces no systematic safety surveillance at all, so absence of a reported harm is not evidence of safety.

Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.

No adverse effects reported in animal work [1][3]

The pre-clinical literature does not report notable toxicity at effective doses. Short studies in healthy animals.

Rodent · in vivo

No human safety data

No human trial has administered MOTS-c. There is no pharmacokinetic profile, no dose-ranging, and no adverse-event dataset.

Evidence gapImportant

Endogenous does not mean safe to administer

MOTS-c being a naturally occurring human peptide says nothing about the consequences of supraphysiological exogenous dosing — the same logic applies to insulin and thyroid hormone.

Principle

03 Dosing ranges

Figures below are documented, not recommended. Study ranges come from published protocols in the stated model; grey-market ranges are what the research community reports using and carry no safety validation of any kind.

Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.

Animal dosing in metabolic models [1][3]

Rodent studies typically use intraperitoneal dosing at milligram-per-kilogram levels over defined periods. Direct conversion to a human subcutaneous dose is not a validated procedure.

Rodent · in vivo

No human dose has been established

Every figure in circulation originates from community practice.

Evidence gap
The fasting instruction, examined

Circulating protocols specify fasted dosing with no food for 30 minutes after, no BCAAs, and only near-zero-calorie caffeine. The reasoning is sound: AMPK responds to low cellular energy state, and amino acids — leucine in particular — signal nutrient abundance through mTOR, which is reciprocally antagonistic to AMPK. Whether this makes a measurable difference to an exogenously administered peptide has never been tested, but it is one of the few community practices with a genuine mechanistic argument behind it.

04 Synergy & interactions

Combination effects. Almost no peptide combination has been studied as a combination in humans; stack logic is overwhelmingly mechanistic inference and community practice. Each linked compound has its own page.

Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.

No combination studies exist

No study has combined MOTS-c with another peptide.

Evidence gap

05 Protocols

Whole schedules — dosing, titration, cycle length, and off-time — as documented in trials, as proposed from mechanism, and as circulated in the research community. Reproduced for study and comparison only.

Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.

Rodent metabolic study design [1]

Diet-induced obesity models with MOTS-c administration, assessed by weight, glucose tolerance, insulin sensitivity, and skeletal muscle glucose uptake.

Rodent · in vivo

Human observational exercise studies [2]

Measurement of circulating and muscle MOTS-c before and after acute exercise and training — observational, not interventional.

Human observational

05b Condition-specific interest

MOTS-c is a real and genuinely interesting piece of biology — a peptide encoded in the mitochondrial genome rather than the nuclear one, which was not thought to happen. That discovery is what makes it worth a page. It is also entirely separate from whether injecting it does anything in a person.

No approval, no trial

MOTS-c has no controlled human trial for any indication. The literature is cell and rodent work plus human observational data associating circulating levels with metabolic status. Association studies in humans and intervention studies in mice do not combine into evidence that intervention works in humans. It received a favourable PCAC vote for the 503A Bulks List — which is a compounding pathway step, not an approval.

Theorized — the core claim, animal and observational

Insulin resistance and type 2 diabetes

Pathophysiology
Insulin resistance in skeletal muscle and liver is central to type 2 diabetes, and AMPK activation is one of the better-validated ways to improve it — it is a principal mechanism of metformin and of exercise.

Mechanistic rationale
MOTS-c activates AMPK and improves insulin sensitivity, glucose disposal and fatty acid oxidation in rodents, including in diet-induced obesity models. Human observational work associates lower circulating MOTS-c with insulin resistance. That association is compatible with MOTS-c being protective, and equally compatible with it being a marker of metabolic health rather than a cause of it — which is what an intervention trial would resolve and none has been run.

Community reports
Used for metabolic optimisation, frequently alongside diet and training changes that would improve insulin sensitivity by themselves.

Components carrying the argument: AMPK activation, folate-methionine pathway effects

Actionable

The metformin comparison

Pathophysiology
AMPK activation is the shared pathway.

Mechanistic rationale
Metformin activates AMPK, costs almost nothing, is taken orally, has been used by hundreds of millions of people over six decades, and has randomised outcome data including in diabetes prevention. If AMPK activation is the goal, the compound that does it with the largest evidence base and the longest safety record already exists and is available on prescription. That comparison is not a rhetorical point; it is the practical answer for most people considering MOTS-c for a metabolic reason.

Community reports
Community discussion rarely makes this comparison, and metformin is often dismissed as unglamorous rather than on evidence.

Components carrying the argument: Same pathway, incomparably better characterised

Theorized — rodent, and the framing oversells it

Exercise capacity and the exercise-mimetic framing

Pathophysiology
Exercise produces coordinated adaptations across muscle, cardiovascular, metabolic and neurological systems, mediated by hundreds of signalling molecules.

Mechanistic rationale
MOTS-c rises with exercise in humans and improves running capacity in aged mice, which is the basis for the exercise-mimetic description. Being one of many molecules that increase during exercise does not make a compound a substitute for exercise — it makes it one readout of it. Exercise itself remains the intervention with mortality data.

Community reports
Reported improvements in endurance and recovery, generally by people who are also training.

Components carrying the argument: AMPK, mitochondrial biogenesis signalling

Theorized — mechanism fits, no PCOS data

PCOS — insulin resistance as the shared driver

Pathophysiology
Insulin resistance drives hyperinsulinaemia, which stimulates ovarian androgen production and suppresses SHBG, raising free testosterone. Improving insulin sensitivity unwinds the loop from the metabolic end.

Mechanistic rationale
The mechanism transfers cleanly — this is the same pathway metformin works through, and metformin is a first-line PCOS treatment for the metabolic phenotype. No study has examined MOTS-c in PCOS, and the compound with the same mechanism and forty years of use in this exact condition is available on prescription.

Community reports
Discussed in PCOS communities on the AMPK rationale, generally alongside inositol.

Components carrying the argument: AMPK — the metformin pathway

Theorized — rodent

Obesity and fatty liver

Pathophysiology
Hepatic steatosis and adiposity both improve with increased fatty acid oxidation and improved insulin sensitivity.

Mechanistic rationale
Rodent studies report reduced adiposity and reduced hepatic steatosis. The effect sizes in mice do not predict effect sizes in people, and this is a field where that gap has been demonstrated repeatedly — the incretins are the exception rather than the rule.

Community reports
Used for body composition, generally as an adjunct.

Components carrying the argument: Fatty acid oxidation, hepatic lipid handling

Theorized — genuinely interesting biology

Longevity and the mitochondrial-derived peptide idea

Pathophysiology
Mitochondrial function declines with age and is one of the more robust correlates of biological ageing.

Mechanistic rationale
The discovery that the mitochondrial genome encodes signalling peptides at all — MOTS-c, humanin and others — is a legitimately significant finding about how mitochondria communicate with the nucleus. That is a reason the field deserves research funding. It is not a reason to inject the peptide, and the distinction between interesting biology and demonstrated therapy is the one this whole cluster turns on.

Community reports
A staple of longevity protocols on the strength of the discovery rather than of any outcome.

Components carrying the argument: Mitochondrial-nuclear retrograde signalling

ClaimEvidenceThe thing to know
Improves insulin sensitivityRodent + human associationAssociation may be marker, not cause
AMPK activationEstablishedMetformin does this, cheaply, with outcome data
Exercise mimeticRodentRising with exercise ≠ substituting for it
PCOSNoneMetformin has 40 years in this exact condition
Obesity / fatty liverRodentMouse effect sizes rarely transfer
LongevityDiscovery-stageInteresting biology ≠ demonstrated therapy
Human trialsNone
What actually has evidence for these conditions

For insulin resistance and type 2 diabetes: metformin first — same pathway, oral, inexpensive, with randomised outcome data including diabetes prevention. SGLT2 inhibitors and GLP-1 agonists have cardiovascular and renal outcome data. Resistance training and aerobic exercise improve insulin sensitivity independently of weight, and dietary change and sleep both move it measurably.

For PCOS: metformin for the metabolic phenotype, combined hormonal contraceptives for hyperandrogenism and cycle control, letrozole first-line for ovulation induction, inositol with reasonable evidence and a benign profile. A 5–10% weight reduction alone restores ovulation in a meaningful proportion.

For fatty liver: 7–10% weight loss produces steatohepatitis resolution in a substantial fraction. Alcohol reduction, treating coexisting diabetes, and resmetirom for biopsy-confirmed disease with fibrosis.

06 Handling, reconstitution & storage

Physical-chemistry reference for laboratory handling of the lyophilised material. Reproduced so that stability and concentration mathematics can be studied — see the calculator for the arithmetic and the reconstitution guide for sterile technique.

Reconstitution

Supplied lyophilised, commonly 5 or 10 mg per vial. At 0.5 mg daily a 10 mg vial is twenty days.

Storage

Lyophilised: −20 °C long-term. Reconstituted: 2–8 °C.

Common vial sizes

Commonly 5 mg and 10 mg lyophilised vials.

Stability notes

A 16-residue peptide with typical peptide stability characteristics; avoid agitation and temperature cycling.

07 Legal & regulatory status

Regulatory status changes and differs by country. This is a summary for orientation, not legal advice — check your own jurisdiction.

Not approved for human use anywhere. MOTS-c has never entered a registered human clinical trial as an administered therapeutic. It is sold exclusively as a research chemical.

Note the asymmetry: MOTS-c has a strong molecular-biology pedigree — it was a genuine scientific discovery published in a leading journal — and essentially no translational human evidence. Those two facts are frequently conflated in marketing.

Regulatory update — current as at August 2026

On 23–24 July 2026 the FDA's Pharmacy Compounding Advisory Committee voted to recommend MOTS-c for inclusion on the Section 503A Bulks List (7–5, two abstentions). It was one of six peptides recommended — alongside BPC-157, KPV, TB-500, MOTS-c, Semax and Epitalon — out of seven considered.

This followed the FDA's announcement of 15 April 2026 removing twelve peptides from Category 2, the designation for substances judged to raise significant safety concerns. That removal stripped away the basis for enforcement against compounders but did not itself authorise anything, leaving these compounds in a regulatory grey area pending the PCAC review.

A PCAC recommendation is not an approval, and the 503A Bulks List is not a drug approval either. It is also worth knowing that July 2026 was the second round: across two sittings in October and December 2024 the same committee reviewed seven substances — among them ipamorelin, kisspeptin-10, AOD-9604, CJC-1295 and thymosin alpha-1 — and rejected all seven. Two separate things are being conflated in almost every write-up of the 2026 decision:

  • The vote is advisory. PCAC recommendations are non-binding. The pathway from here runs: removal from Category 2 (done, April 2026) → PCAC recommendation (done, July 2026) → placement in Category 1 through notice-and-comment rulemaking, which commonly takes eight to twelve months → and the HHS Secretary must sign off on any addition to the list. Nothing is lawfully compoundable on the strength of the vote alone.
  • Even a successful listing would not make these approved drugs. Inclusion on the 503A Bulks List permits a licensed compounding pharmacy to use the substance in a compounded preparation for an individual patient with a prescription. It says nothing about the compound being demonstrated safe and effective — no efficacy trial is required, and none of these has one.
  • It would not legitimise research-chemical supply. A compounding pathway runs through a licensed pharmacy and a prescriber. Grey-market vials labelled "research use only" are not that, and nothing in this decision changes their status.

Regulatory and trial claims re-checked against primary sources on 16 August 2026. Checked: PCAC vote 23-24 July 2026 and the 503A pathway. Approvals, trial readouts and compounding decisions move faster than anything else on this page — a date here means someone looked, not that nothing has changed since.

Anti-doping

Athletes subject to WADA, USADA, UKAD, NCAA or military testing should assume any peptide is prohibited unless they have verified otherwise against the current WADA Prohibited List. Several classes here (growth-hormone secretagogues, TB-4 analogues, metabolic modulators) are explicitly named. Check the current list — it is republished annually.

§ Sources & further reading

Links resolve to PubMed records, trial registries, publisher pages or primary documents. Where a body of work rather than a single paper is cited, the link opens a PubMed query so the full result set — including newer papers than this page — can be reviewed. Verify every claim against the primary source before relying on it.

  1. 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.Pre-clinical / animal study
  2. Reynolds JC, et al. MOTS-c and exercise: circulating and skeletal muscle responses in humans. (see also PubMed query)Human clinical study
  3. MOTS-c: A novel mitochondrial-derived peptide regulating muscle and fat metabolism. Review.Review or meta-analysis
  4. The mitochondrial-derived peptide MOTS-c is a regulator of plasma metabolites and enhances insulin sensitivity.Pre-clinical / animal study
  5. MOTS-c Functionally Prevents Metabolic Disorders. Review, 2023.Review or meta-analysis
  6. PubMed: MOTS-c — all indexed literature (live query)Database or literature search
Reminder

For educational and research reference only. Nothing on this site is medical advice, a recommendation, or an instruction to administer any substance to a human being. Every figure on this page is a record of what has been reported, not a recommendation. Full disclaimer.