MOTS-c (Mitochondrial Open reading frame of the Twelve S rRNA type-c) is a peptide of 16 amino acids whose coding sequence sits inside mitochondrial DNA rather than in the nucleus. It belongs to a small family known as mitochondrial-derived peptides (MDPs), alongside humanin and the SHLP series. It was identified and characterised by Lee et al., Cell Metabolism, 2015.

How does MOTS-c activate AMPK?

Indirectly. In the founding 2015 work, MOTS-c was shown to interfere with the folate-methionine one-carbon cycle, which causes the intermediate AICAR to build up. AICAR is a well-characterised endogenous AMPK activator, so AMPK signalling rises as a downstream consequence rather than through MOTS-c binding a surface receptor. Later work reported that under metabolic stress MOTS-c also translocates to the nucleus and associates with stress-responsive regulatory elements.

Is MOTS-c banned by WADA?

Yes. MOTS-c is named on the World Anti-Doping Agency Prohibited List in class S2 — peptide hormones, growth factors, related substances and mimetics — which is prohibited at all times, both in and out of competition. USADA publishes athlete guidance on it for the same reason. This is one of several reasons the material is supplied strictly as a laboratory reagent and not for human use of any kind, athletic or otherwise.

What does the MOTS-c literature actually show?

The strongest findings are preclinical. In mice, MOTS-c administration opposed high-fat-diet-induced obesity and insulin resistance (Lee et al., 2015). Reynolds et al. (Nature Communications, 2021) reported that MOTS-c behaves as an exercise-responsive peptide and that treatment in aged mice improved physical capacity. Human data is largely observational — associations, not demonstrated effects — and should not be read as evidence of efficacy in people.

How is research-grade MOTS-c stored and reconstituted?

It ships as a lyophilized powder, sealed and lyophilized under nitrogen, stable for about 18 months at -20 °C in the unopened vial. For in-vitro work it is reconstituted with bacteriostatic water added slowly down the inner wall of the vial and swirled, never shaken. Reconstituted solution is kept at 2–8 °C, protected from light, and used within roughly 14 days.

MOTS-c: The Mitochondrial-Derived Peptide, Its AMPK Mechanism & Research Status

MOTS-c is a 16-amino-acid peptide encoded not in the cell nucleus but inside the mitochondrial genome, within the 12S rRNA gene. It was first described by Lee and colleagues in Cell Metabolism in 2015, where it was shown to interfere with the folate cycle, cause AICAR to accumulate, and activate AMPK — the cell's main energy sensor. Nearly all published work is in mice, cell culture and human observational cohorts. It is supplied here as a lyophilized research reagent, is not a medicine, and is prohibited in sport by WADA.

What MOTS-c is, and why its address matters

Almost every peptide in a research catalogue is a nuclear product: the gene sits on a chromosome, the protein is built in the cytoplasm, and the mitochondrion is treated as a passive power plant. MOTS-c breaks that arrangement. Its 16-codon open reading frame is located inside mitochondrial DNA, in the 12S ribosomal RNA gene — the same short circular genome that mitochondria carry as a relic of their bacterial ancestry.

That address is the whole story. It means the organelle is not only receiving instructions from the nucleus, it is sending them back. MOTS-c is the best-characterised example of what the field calls retrograde signalling: a message travelling from mitochondrion to nucleus. It belongs to a small family, the mitochondrial-derived peptides (MDPs), whose other known members are humanin and the SHLP series.

The founding paper is Lee et al., “The Mitochondrial-Derived Peptide MOTS-c Promotes Metabolic Homeostasis and Reduces Obesity and Insulin Resistance”, Cell Metabolism, 2015. Everything written about MOTS-c since traces back to it, and any vendor page that describes the compound without referencing it is paraphrasing someone else’s summary.

The mechanism: folate cycle, AICAR, then AMPK

MOTS-c is usually introduced as “an AMPK activator”, which is true but skips the interesting part. It does not appear to bind a cell-surface receptor and switch AMPK on directly. The route described in the 2015 work is metabolic and indirect:

Step	What is reported to happen	Consequence in the model
1. Folate cycle	MOTS-c interferes with the folate-methionine one-carbon cycle	Purine biosynthesis flux is disturbed
2. AICAR accumulates	AICAR, an intermediate of de-novo purine synthesis, builds up	AICAR is a classical endogenous AMPK activator
3. AMPK activation	AMPK signalling rises downstream	Cells shift toward catabolic, energy-generating programmes
4. Nuclear translocation	Under metabolic stress the peptide has been reported to move into the nucleus	Association with stress-responsive regulatory elements

A useful way to hold this in mind: AMPK is the cell’s low-fuel warning light. Most pharmacological AMPK activators press the light directly. MOTS-c instead nudges a metabolic side-road (one-carbon metabolism) until a natural activator piles up behind the roadblock, and the warning light comes on by itself. That is a mechanistically different — and, for researchers, a more interesting — kind of lever.

The nuclear-translocation arm was reported later, notably in work from the same group (Kim and colleagues, Cell Metabolism, 2018), describing MOTS-c relocating to the nucleus under metabolic stress and associating with antioxidant-response regulatory elements. If that holds up, MOTS-c is doing two jobs: shifting metabolite pools in the cytoplasm and acting as a transcriptional co-regulator in the nucleus.

What the published literature actually reports

This is where a guide has to be careful. The MOTS-c dataset is real but it is not human efficacy data, and the distinction matters more here than for most compounds because the popular write-ups blur it constantly.

Mouse metabolic models

In the 2015 Cell Metabolism work, MOTS-c administration in mice opposed the metabolic consequences of a high-fat diet — the treated animals resisted diet-induced obesity and the associated insulin resistance, with the effect traced back to AMPK activation in skeletal muscle. These are mouse findings, in a controlled dietary challenge, at doses chosen for a rodent model.

Exercise and age-related decline

The second anchor is Reynolds et al., Nature Communications, 2021, which characterised MOTS-c as an exercise-responsive, mitochondrially encoded regulator of muscle homeostasis. Two threads run through it: MOTS-c levels respond to exercise, and MOTS-c treatment in aged mice improved measures of physical capacity relative to controls. Again: mice for the intervention arm, humans only for the observational exercise-response measurements.

Human genetics — association, not effect

A mitochondrial variant in the MOTS-c reading frame (m.1382A>C, producing a K14Q substitution) has been reported in Japanese cohorts in connection with longevity and with metabolic phenotypes (Fuku et al., Aging Cell, 2015). This is population genetics: it links a sequence variant to an outcome in a specific population. It does not show that administering the peptide produces that outcome in anyone.

How to read this evidence base. Intervention data for MOTS-c is preclinical: mice and cell culture. Human data is observational — levels measured, variants associated. No published randomised controlled trial establishes an effect of administered MOTS-c in people. Any source that states otherwise, or that quotes a human percentage improvement, is over-reading the literature.

MOTS-c and the WADA Prohibited List

If you search for MOTS-c, one of the first results you will meet is an anti-doping organisation rather than a journal — and that is not an accident. MOTS-c is named on the World Anti-Doping Agency Prohibited List, in class S2 (peptide hormones, growth factors, related substances and mimetics). Class S2 substances are prohibited at all times: in competition and out of competition alike. USADA, the United States anti-doping agency, publishes athlete-facing guidance on it for exactly this reason.

We state this plainly because it is verifiable, and because it reinforces rather than undermines what this material is. Two practical consequences follow.

An athlete subject to anti-doping rules must not use it, full stop. Prohibited at all times means an out-of-competition test is enough. There is no “off-season” window and no threshold that makes it acceptable.
It underlines the research-use-only frame. MOTS-c sold as a research reagent is not for human use of any kind. Sporting use is simply the case where a second, independent set of rules also applies.

The current list is published and updated annually by WADA; researchers and coaches should check the official WADA Prohibited List rather than any second-hand summary, including this one.

Handling MOTS-c in the laboratory

MOTS-c ships as a white lyophilized powder in a sealed glass vial, lyophilized under nitrogen. Handling is the same discipline as any short peptide, with one difference worth flagging: the reconstituted working window is shorter than for the robust repair peptides, so it is worth planning assays around the vial rather than opening one speculatively.

Parameter	Lyophilized	Reconstituted
Storage temperature	-20 °C, sealed vial	2–8 °C
Working window	~18 months	~14 days
Light and moisture	Protect from both	Protect from direct light
Typical diluent	—	Bacteriostatic water (0.9% benzyl alcohol)
Concentration from a 20 mg vial	—	10 mg/mL at 1 mL · 5 mg/mL at 2 mL

The reconstitution mechanics matter more than most people expect. Bring the vial and the diluent to room temperature, disinfect both stoppers, then run the water slowly down the inner wall of the vial rather than jetting it onto the powder cake. Swirl or roll the vial between the palms until dissolved — never shake, since shear and foaming are a genuine route to denaturing a peptide before an assay ever starts. Inspect the solution: it should be clear and free of particulates. The concentration arithmetic, draw volumes and a worked table are in the bacteriostatic water and reconstitution guide.

How to verify a MOTS-c lot before you trust it

MOTS-c is a 16-residue peptide, which puts it well within reach of routine solid-phase synthesis — and that is precisely why lot verification matters. Short peptides are easy to make and easy to make badly, and a truncated or deletion sequence looks identical to the eye. Four checks separate a documented lot from a hopeful one.

HPLC purity above 99%, on a chromatogram, not a claim. The trace should show one dominant peak. A shoulder or a cluster of small satellite peaks usually means deletion sequences from incomplete coupling steps.
Mass spectrometry confirming identity.Purity says “one thing is in the vial”. Mass spec says which thing. Without it a highly pure wrong peptide passes the purity test perfectly.
A lot-specific Certificate of Analysis, not a generic one.The document must carry a batch number matching the vial label and a date. A COA that covers “MOTS-c” in the abstract, with no batch identifier, proves nothing about the vial in your hand. Independent laboratories are used for this work — Janoshik Analytical is the one most commonly seen in this field.
Stated salt form and net peptide content. Peptides are typically supplied as acetate salts; the labelled mass and the actual peptide mass are not the same number, which matters as soon as you calculate a molar concentration.

The broader framework — what a COA proves, which purity benchmarks are meaningful and the red flags that recur across suppliers — is set out in the complete research peptides guide.

Where MOTS-c sits next to other metabolic reagents

Researchers rarely arrive at MOTS-c in isolation; they arrive comparing it to the pharmacological metabolic compounds. The distinction is worth drawing clearly, because these are not interchangeable tools.

Compound	Origin	Primary axis studied
MOTS-c	Endogenous, mitochondrially encoded (16 aa)	Folate cycle → AICAR → AMPK; mitochondrial retrograde signalling
Retatrutide	Synthetic incretin analogue	GLP-1 / GIP / glucagon receptor agonism
NAD+	Endogenous coenzyme	Sirtuin and PARP substrate; redox and DNA-repair signalling

The contrast is that retatrutide is a designed drug candidate acting on cell-surface receptors, while MOTS-c and NAD+ are endogenous molecules studied as levers on the cell’s own energy-sensing machinery. That is why MOTS-c and NAD+ frequently appear together in mitochondrial-ageing research designs, and why the AMPK and sirtuin literatures overlap so heavily.

If you are assembling a panel rather than a single compound, the full range of research-grade material, strengths and per-vial pricing is on the research peptides catalog, and the lot data for this specific compound sits on the MOTS-c product page.

For research use only. Not for human or animal use. Not a drug and not a supplement. The findings summarised above describe published preclinical and observational research and are not medical advice, dosing guidance or a claim of efficacy. MOTS-c is prohibited at all times under the WADA Prohibited List (class S2). Citations: Lee et al., Cell Metabolism 2015; Kim et al., Cell Metabolism 2018; Reynolds et al., Nature Communications 2021; Fuku et al., Aging Cell 2015.