Short answer: MOTS-c itself has never been tested in a published human trial. The closest human data comes from CB4211, a modified version developed by the company CohBar: in a 2021 phase 1a/1b study, it caused no serious adverse events, and the only side effect seen in more than 10% of people was mild to moderate injection-site reactions. It also lowered blood glucose by 6% versus placebo in four weeks, but did not beat placebo on liver fat. Then the company stopped. Here is what that tells you.
What MOTS-c is
MOTS-c is a 16-amino-acid peptide encoded not in the cell nucleus but in mitochondrial DNA, discovered in 2015 by Changhan David Lee and Pinchas Cohen. In mice it acts like an “exercise signal”: it activates AMPK, improves insulin sensitivity and prevented diet-induced obesity. Levels fall with age in some studies. For its place among other mitochondrial compounds, see MOTS-c, SS-31 and NAD+.
The only human data: CB4211
| Study | Detail |
|---|---|
| Compound | CB4211, “a novel and improved analog of MOTS-c” (not MOTS-c itself) |
| Phase 1a | 65 healthy adults |
| Phase 1b | 20 adults with obesity and fatty liver (11 drug, 9 placebo), 25 mg daily by injection for 4 weeks |
| Liver fat | −5.03% vs −4.88% placebo: no meaningful difference |
| Blood glucose | −6% vs no change: statistically significant |
| Body weight | Only “a trend” |
CohBar did not advance CB4211 into larger trials.
Side effects
- Injection-site reactions (mild to moderate, transient) were the only adverse events in more than 10% of CB4211 participants.
- No serious adverse events in either part of the study.
- For MOTS-c itself, users report injection-site soreness and, less often, fatigue or a feeling like after exercise. These are anecdotal.
- Unknowns: long-term effects, effects of the unmodified peptide in humans, and blood-sugar effects in people on diabetes medication.
| Health Canada | Not authorized. MOTS-C is named in Health Canada’s April 2026 advisory on unauthorized injectable peptides. |
|---|---|
| FDA (USA) | Not approved. In July 2026 an FDA advisory committee recommended allowing pharmacy compounding of MOTS-c; the vote is non-binding. |
See TrueLabs MOTS-C and its COA →
Frequently asked questions
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What are the side effects of MOTS-c?
MOTS-c has no published human trials. Its analog CB4211 caused no serious adverse events in a phase 1 study; mild to moderate injection-site reactions were the only effect seen in more than 10% of participants.
Has MOTS-c been tested in humans?
Not MOTS-c itself. An improved analog, CB4211, was tested in 85 people in a 2021 phase 1a/1b study.
Does MOTS-c lower blood sugar?
In mice it improves insulin sensitivity. In the CB4211 human study, glucose fell 6% vs placebo over four weeks.
Is MOTS-c FDA approved?
No. An FDA advisory committee recommended allowing compounding in July 2026, but that vote is non-binding and is not an approval.
Is MOTS-c legal in Canada?
MOTS-C is not authorized by Health Canada and is named in its April 2026 advisory on unauthorized injectable peptides.
Related reading
- What is MOTS-c? Discovery, mechanism and evidence
- MOTS-C, SS-31 and NAD+: the mitochondrial toolkit
- SS-31 (elamipretide): the first approved mitochondrial peptide
- NAD+ injection side effects
References
- Lee C, Zeng J, Drew BG, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443–454. PubMed
- CohBar. Positive topline results from the phase 1a/1b study of CB4211. August 10, 2021. BioSpace
- Health Canada. Think twice before injecting peptides bought online. April 9, 2026. Health Canada
All TrueLabs products are sold for in vitro and laboratory research use only. They are not intended for human or veterinary use, and nothing in this article is medical advice.