Evidence scope: this selected answer uses the abstract of a 2026 exercise review and the full text of a 2020 human observational study. It is not an exhaustive trial, safety or regulatory review, and it provides no treatment or dosing instructions.
The selected studies do not establish that taking MOTS-c improves fatigue. Measurements of naturally occurring MOTS-c and responses to exercise are different from a trial of an administered peptide. Missing treatment evidence also does not prove that a treatment cannot work.
What the exercise review actually covers
The 2026 systematic review asks how physical activity affects mitochondrial-derived peptides, a group including humanin and MOTS-c. Its abstract reports searches covering 2016 to 2025, 435 identified records and nine included studies. These are not described as nine human trials of administered MOTS-c for fatigue.[1]
Most included studies reported a trend toward increased peptide levels after exercise. The authors describe limited and heterogeneous evidence and call for controlled and longitudinal research, particularly in humans. This is a review of existing research, not a new treatment experiment. Only its abstract was read for this answer.[1]
Measuring a naturally occurring peptide before and after exercise is different from giving participants that peptide and measuring fatigue. The review abstract cannot support a complete census of every human administration, pharmacokinetic study or adverse event. This answer makes no such claim.
Blood and muscle measurements answer different questions
A 2020 cross-sectional study in healthy men found lower circulating MOTS-c with age alongside higher skeletal-muscle expression in middle-aged and older groups than in younger men. Blood and muscle therefore did not show the same age-related pattern. The report also describes differences between the older blood and muscle samples.[2]
The study measured naturally occurring MOTS-c. It did not test administered MOTS-c as a fatigue treatment. An age association cannot establish that a lower blood value causes fatigue, define a clinical deficiency threshold or show that replacement improves symptoms.[2]
What a useful fatigue answer would need
A treatment claim needs evidence matched to the participants, administered product and route, comparator, measured fatigue outcome and safety follow-up. Natural-level associations cannot fill those gaps. Evidence that is insufficient to establish a benefit is also insufficient to establish that a benefit is impossible.
The same outcome discipline applies to comparisons. Participant counts from studies of NAD+ or GLP-1 medicines on glucose, lipids or cardiovascular events do not, by themselves, establish which product improves fatigue. This selected answer does not rank those products for fatigue.
What remains unknown about safety
These selected reports cannot quantify the risks of self-administering MOTS-c or establish a safe regimen. Missing safety evidence is not a clean safety record. This answer does not claim that no human has ever received MOTS-c or that no adverse event has ever occurred.
For help reading research claims, use the MaxHuman guide and keep the study population, intervention and outcome together.
This article is for research and informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. It provides no treatment or dosing instructions. Consult a qualified clinician for individual medical decisions.
References
- Mitochondrial-derived peptides (MDPs) activated by physical exercise as therapeutic targets for metabolic disorders: A systematic review.. Physiology international, 2026.
- Increased expression of the mitochondrial derived peptide, MOTS-c, in skeletal muscle of healthy aging men is associated with myofiber composition.. Aging, 2020.
