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Peptide Insider

Mitochondrial-derived peptide

MOTS-c

Also known as Mitochondrial ORF of the 12S rRNA type-c · Mitochondrial-derived peptide

Preclinical ResearchPRECLINICALFDA approved: No

MOTS-c was described in 2015 as something genuinely new: a peptide encoded not in the nuclear genome but within mitochondrial DNA, in the 12S ribosomal RNA region, and detectable in circulating human plasma. That combination — mitochondrially encoded, systemically circulating — made it one of the first credible examples of a mitochondrion communicating with the rest of the body through a hormone-like signal. The original work reported that MOTS-c targets skeletal muscle, inhibits the folate cycle and purine biosynthesis, accumulates AICAR and activates AMPK, and that treatment prevented diet-induced obesity and insulin resistance in mice. It is one of the more interesting findings in metabolic biology of the past decade. It is also, in humans, entirely untested.

Written by Peptide Insider Editorial TeamPublished Last reviewed

The Insider Summary

What it is
A 16-amino-acid peptide encoded within mitochondrial DNA, circulating in human plasma — one of a small family of mitochondrial-derived peptides.
Why researchers are interested
It suggests mitochondria act as signalling organs, not just power plants. In mice, MOTS-c activates AMPK through the folate–purine–AICAR axis and prevents diet-induced obesity and insulin resistance; later work links it to exercise response and age-related physical decline.
Evidence
Preclinical. The foundational work is in mice, rats and human cell lines. Human plasma measurement confirms it circulates; that is an observational finding about an endogenous molecule, not evidence that administering it does anything.
Regulatory status
Not approved by the FDA for any indication, and not in any clinical development programme we have identified. FDA lists MOTS-c among substances whose 503A compounding nominations were withdrawn.
Bottom line
MOTS-c is a legitimate and exciting piece of basic science that has not taken a single step toward clinical evaluation. It is sold as though it were an exercise mimetic for humans; the published record supports calling it a promising mouse result.

Quick reference

Compound
Mitochondrial-derived peptide
Research areas
Mitochondrial ResearchMetabolic ResearchLongevity Research
Evidence level
PRECLINICAL
Research status
Preclinical Research
FDA approved
No
Human clinical evidence
None published
Sequence
A 16-amino-acid peptide encoded within the mitochondrial 12S rRNA region
Last reviewed
17 September 2026

What is MOTS-c?

Mitochondria carry their own small circular genome, a remnant of the bacterial ancestry of the organelle. For most of the modern era it was assumed to encode only components of the respiratory chain and the RNA machinery needed to make them. MOTS-c belongs to a small set of peptides encoded by short open reading frames within that mitochondrial genome — in this case within the 12S rRNA region.

Two findings made the 2015 report significant. First, MOTS-c was detectable in circulating human plasma, which makes it hormone-like rather than purely intracellular. Second, its metabolic effects in mice were substantial and mechanistically traceable: inhibition of the folate cycle, AICAR accumulation, AMPK activation, and prevention of both age-dependent and high-fat-diet-induced insulin resistance [1].

A 2021 study extended the picture toward exercise biology, reporting that MOTS-c is induced by exercise and regulates age-dependent physical decline and muscle homeostasis [2].

What is MOTS-c being studied for?

Metabolic regulation. The founding research line: insulin sensitivity, glucose homeostasis and diet-induced obesity, in mice.

Exercise biology and muscle ageing. Work reporting that MOTS-c is exercise-induced and influences physical capacity and muscle homeostasis in ageing mice. This is the source of the "exercise in a vial" framing that appears in consumer marketing — a framing the underlying papers do not make.

Ageing. Because circulating mitochondrial-derived peptide levels vary with age, MOTS-c appears in the ageing-biology literature. That literature is observational and preclinical.

What does not exist: published, controlled human trials of MOTS-c administration for any endpoint. Measuring endogenous MOTS-c in human plasma is not the same as testing MOTS-c as an intervention in people, and conflating the two is the most common error in writing about this compound.

How does MOTS-c work?

The mechanism described in the original characterisation is unusually specific. MOTS-c inhibits the folate cycle and de novo purine biosynthesis, leading to accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an endogenous activator of AMP-activated protein kinase (AMPK). AMPK activation shifts cells toward catabolic, energy-generating metabolism and increases glucose uptake in skeletal muscle. Later work reported that MOTS-c translocates to the nucleus under metabolic stress and influences the expression of nuclear stress-response genes — a mitochondrial peptide acting as a nuclear regulator.

Research and clinical evidence

The table below grades the published record separately for each research area, because a compound can be well studied in one context and entirely unstudied in another. Grades follow the Peptide Insider evidence taxonomy.

Evidence level by research area
Research areaEvidence levelWhat the published record shows
Insulin sensitivity and metabolic regulationPRECLINICALMouse studies report prevention of age-dependent and diet-induced insulin resistance and of diet-induced obesity, with a traceable AMPK-dependent mechanism.
Exercise response and muscle ageingPRECLINICALReported as exercise-induced and as a regulator of age-dependent physical decline and muscle homeostasis in animal models.
Any human therapeutic useINSUFFICIENTNo published controlled human trials of administered MOTS-c have been identified for any indication.

Animal studies

Findings in animal models. Historically, most results at this stage do not reproduce in humans.

The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance[1]

2015
Design
Mechanistic study across mouse and rat models plus human cell lines
Population
C57BL/6 and CD-1 mice, rats; HEK293, HeLa and L6 myocyte cultures

FindingsIdentified MOTS-c as a 16-amino-acid peptide encoded in the mitochondrial 12S rRNA that targets skeletal muscle, inhibits the folate cycle and purine biosynthesis, accumulates AICAR and activates AMPK. Treatment prevented age-dependent and high-fat-diet-induced insulin resistance and diet-induced obesity. MOTS-c was detected in human plasma.

LimitationsAnimal and cell-culture work. The human component was measurement of endogenous circulating peptide, not administration. No human dosing, pharmacokinetics or outcomes.

MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis[2]

2021
Design
Animal study with exercise intervention and ageing cohorts

FindingsReported that MOTS-c expression responds to exercise and that treatment influenced physical capacity and muscle homeostasis in ageing animals.

LimitationsPreclinical. Reported effects on running capacity in mice do not establish any effect on human exercise capacity or ageing.

No qualifying human clinical studies. We have not identified published, controlled human trials of this compound for the research areas described above. That absence is the most important fact on this page.

FDA and regulatory status

MOTS-c is not approved by the FDA for any indication, and we have not identified any registered clinical development programme for it.

FDA lists MOTS-c among substances nominated for the section 503A bulk drug substances list whose nominations were withdrawn [3].

Material sold under this name is a research chemical. Because MOTS-c is a short, endogenously occurring sequence, it is straightforward to synthesise — which lowers the barrier to selling it and does nothing to establish that administering it is safe or useful.

Safety and known risks

Risks are separated into what is documented, what is plausible but unestablished, and what has not been studied. The third column is usually the longest one for an unapproved compound, and it is not a reassurance.

Known risks

Documented in regulatory labelling or published trial safety data.

None identified in the sources reviewed.

Potential risks

Plausible on mechanism or drug-class grounds, but not established for this compound.

  • AMPK is a master metabolic regulator involved in glucose uptake, lipid metabolism, autophagy and cell growth. An agent that activates it systemically would be expected to have broad effects, and the consequences of doing so chronically in humans are unknown in both directions.
  • Research-chemical supply carries the usual identity, purity and sterility uncertainties.

Unknown or insufficiently studied

Questions the published record does not currently answer.

  • No published human pharmacokinetic data.
  • No published human safety data of any kind.
  • No published data on interactions with metabolic medicines such as metformin, which also acts through AMPK-related pathways.
  • No data on long-term consequences of exogenous administration of a mitochondrially encoded signalling peptide.

Frequently asked questions

Has MOTS-c been tested in humans?
Not as an intervention. MOTS-c has been measured in human plasma and in human cell lines, which tells us it circulates endogenously. We have identified no published controlled trials in which MOTS-c was administered to people and an outcome measured.[1]
Is MOTS-c an “exercise mimetic”?
That phrase comes from marketing, not from the papers. Research has reported that MOTS-c is exercise-induced and that treatment affected running capacity and muscle homeostasis in mice. Extending that to humans is an assumption, not a finding.[2]
What makes MOTS-c scientifically unusual?
It is encoded by mitochondrial DNA rather than the nuclear genome, and it circulates systemically. That combination supports the idea that mitochondria signal to the rest of the body — a genuinely novel concept in cell biology.
Is MOTS-c FDA approved?
No. It has no approved indication, and FDA lists it among substances whose 503A compounding nominations were withdrawn.[3]

Continue reading

Peptide Science

What Are Peptides?

Peptides are short chains of amino acids. What separates a peptide from a protein, why the body uses them as signals, and why that makes them both useful drugs and difficult ones.

Regulation

What Does “Research Use Only” Mean?

The phrase appears on nearly every research peptide sold online. It is a statement by the seller about intended use — not a regulatory designation, and not a safety assessment.

References

Peptide Insider cites primary sources wherever they exist — regulatory documents, trial registrations and peer-reviewed literature — in preference to secondary summaries.

  1. 1.
    Lee C, Zeng J, Drew BG, et al.. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metabolism, 2015;21(3):443–454.
    Peer-reviewedDOI: 10.1016/j.cmet.2015.02.009
  2. 2.
    Reynolds JC, Lai RW, Woodhead JST, et al.. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nature Communications, 2021;12:470.
    Peer-reviewedDOI: 10.1038/s41467-020-20790-0
  3. 3.
    U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks. FDA, 2026;Page last updated 22 April 2026.
    Regulatory