MOTS-c
Mitochondrial-derived peptide · No brand name. Sold as MOTS-c free base or MOTS-c acetate
- UK status
- Unlicensed medicine
- Availability
- Research use only
- Evidence base
- No human trials of the peptide itself
- Controlled drug
- No
Sequence
16 amino acids, encoded within the mitochondrial 12S rRNA gene. Verify notation against the literature before publishing one.
The short version
What it does
Sold for metabolic health: better insulin sensitivity, fat loss, exercise capacity, and slowing age-related decline. None of that has been tested in people.
How it does it
Your cells contain mitochondria, the parts that make energy, and they carry their own small set of DNA. This peptide is written in that DNA rather than the DNA in the cell nucleus, and it appears to act as a signal telling the body to handle fuel differently when energy is short.
The catch
The FDA's reviewers found no human clinical studies at all for it. Not thin evidence, none. The only completed controlled trial used a different, modified version of the molecule, not this one.
Everything below goes into the detail, with sources.
MOTS-c is the most scientifically interesting compound in this register, and one of the least tested in humans. Both of those things are true at once, and holding them together is the whole exercise.
01What it is
Almost every peptide your body makes is encoded in the DNA in your cell nuclei. MOTS-c is not. It is encoded inside the mitochondrial 12S rRNA gene, in the separate small genome your mitochondria carry, and it is 16 amino acids long.
That matters more than it sounds. It means your mitochondria are not simply power stations taking orders from the nucleus. They appear to send signals of their own that affect metabolism across the whole body. MOTS-c was one of the first of these mitochondrial-derived peptides identified, and the discovery opened a genuinely new area of biology.
"Encoded in your mitochondrial DNA" is a fascinating fact and it does a great deal of marketing work. But where a molecule comes from tells you nothing about whether injecting extra of it helps a person. Interesting origin, unknown effect.
02How it came about
MOTS-c was identified by researchers at the University of Southern California in 2015, in work on the mitochondrial genome. Animal studies followed reporting effects on insulin sensitivity, weight, exercise capacity and muscle wasting, largely in mice and rats.
A biotechnology company took a modified analogue called CB4211 into human trials. That analogue, not MOTS-c itself, is the source of the only completed controlled human data. Native MOTS-c has no completed phase 2 or phase 3 programme, though a phase 2a study in prediabetes has reportedly been registered.
It reached the FDA's Pharmacy Compounding Advisory Committee in July 2026, nominated for obesity and osteoporosis, and the committee voted 7 to 5 with two abstentions to recommend it for compounding.
03UK legal and licensing status
MOTS-c has no MHRA authorisation for anything. Supplying it for human use in the UK without a marketing authorisation is prohibited under the Human Medicines Regulations 2012. It is not a controlled drug. It is sold as a research chemical labelled not for human consumption.
The July 2026 FDA committee recommendation applies to US compounding pharmacies and is not an approval. It requires formal rulemaking to take effect, typically 8 to 12 months, the FDA is not bound by it, and it has no bearing on UK law or MHRA enforcement.
04How it works
The proposed mechanism, from laboratory and animal work, centres on an enzyme called AMPK, which acts as a cellular fuel gauge. When energy is low, AMPK switches cells towards burning fuel rather than storing it. MOTS-c appears to activate that pathway, and also to move into the cell nucleus under stress and influence which genes are switched on.
Separately, animal studies have reported that MOTS-c reduces muscle wasting from disuse or from steroid exposure. Laboratory work in human muscle cells has looked at the same question.
None of this is a human outcome. It is a plausible mechanism looking for a trial.
05What it is not
Claims that attach themselves to this compound and do not hold up.
- Not a tested metabolic treatment. The FDA's reviewers found no human clinical studies supporting the proposed uses.
- Not the same as CB4211. The one completed controlled human trial used a modified analogue. Research on it is routinely presented as research on MOTS-c.
- Not FDA approved. A compounding recommendation is several legal steps and many months away from anything resembling approval, and is not approval even then.
- Not a GLP-1 alternative. Different mechanism entirely, and nothing about it has been shown to produce weight loss in humans.
06What the evidence shows
The animal literature is real and reasonably substantial: effects on insulin sensitivity, body weight, exercise capacity and muscle atrophy across rodent models.
In its July 2026 review the FDA reported finding no human clinical studies at all for MOTS-c supporting the nominated uses. The one completed controlled trial in humans used CB4211, a different molecule. Researchers themselves note the poor translation of rodent muscle-wasting findings into effective human therapies.
So the honest position is that this is early biology. That is not an insult. Most drugs start here. It is simply a long way from a treatment, and nobody selling it can close that distance.
Everything about human effect and human safety. There is no approved route, no dose established in people, no long-term data, and no standardised preparation. Two different chemical forms are sold under the same name.
07Reported harms
No authoritative side effect profile exists, because that comes from regulated trials and there have not been any. The FDA has stated it lacks important information about whether MOTS-c would cause harm when administered to humans, and raised immunogenicity, peptide-related impurities and product characterisation as specific concerns.
The unregulated supply risks apply in full: unverified identity, purity and concentration, non-sterile preparation, and no route to report harm or recall a batch.
08Interactions and cautions
Unknown. Interaction data comes from development programmes and there has not been one. Because the proposed mechanism involves glucose handling and insulin sensitivity, anyone taking diabetes medication is in genuinely uncharted territory, and no prescriber can advise on a compound with no human data.
09Stopping
Undocumented. No established effect to lose and no withdrawal syndrome described.
10Monitoring
Nothing formal exists. If anyone were monitoring sensibly given the proposed mechanism, fasting glucose and HbA1c would be the obvious markers, which is not what the marketing focuses on.
11Questions worth asking
Take these to a doctor or pharmacist. A good clinician will not mind being asked, and the answers are specific to you in a way nothing on this page can be.
- Given there are no human studies at all, what am I basing this on?
- Is the research I have read about MOTS-c, or about the CB4211 analogue?
- Is there a licensed treatment for what I am actually trying to address?
12Common questions
Did the FDA approve MOTS-c in July 2026?
No. An advisory committee recommended it for a list of substances that US compounding pharmacies may prepare. That is not approval, the FDA is not bound by it, and it needs formal rulemaking that typically takes 8 to 12 months. It changes nothing in the UK.
Is MOTS-c legal in the UK?
It has no MHRA authorisation, so supplying it for human use is prohibited. It is not a controlled drug, and it can be sold lawfully as a research chemical labelled not for human consumption.
Does MOTS-c work for weight loss or diabetes?
Unknown in humans. Animal studies report effects on insulin sensitivity and body weight. The FDA found no human clinical studies supporting the nominated uses, and the one completed controlled human trial used a different molecule.
Why is a mitochondrial peptide interesting?
Because it suggests mitochondria send metabolic signals to the rest of the body rather than only responding to instructions. That is a real shift in understanding. It is a reason to fund trials, not a reason to inject something.
13Sources
Links go to the authoritative source. Where a document sits behind a paywall or moves around, the full citation is given so you can find it yourself.
- Bulk drug substances review, MOTS-cFDA
- PCAC July 2026 meeting materialsFDA
- MOTS-c and humanin in human skeletal muscle cellsPubMed, 2026
- MOTS-c discovery and mitochondrial-derived peptidesPubMed
- Unlicensed medicines guidanceMHRA
14Change history
Every substantive change to this record is logged here with its date. Corrections are made openly, not quietly.
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