Is MOTS-c banned? What athletes should know about the exercise studies behind it

MOTS-c reaches the gym through a marketing nickname: “exercise in a vial.” That phrase sounds like a training shortcut, which is exactly why it is worth checking against the studies. This page looks at the athlete angle specifically. It explains why the peptide caught the sport crowd’s attention, what the exercise-capacity studies actually measured (and in which species), why the human data on athletes point in more than one direction, and where MOTS-c sits on the anti-doping list. For the full overview of the molecule, see the hub guide to MOTS-c; for the metabolic research in depth, see what MOTS-c’s metabolic research shows.

What is MOTS-c?

MOTS-c is a 16-amino-acid peptide encoded in mitochondrial DNA rather than in the cell nucleus. The 2015 Cell Metabolism paper that named it reported that its “primary target organ appears to be the skeletal muscle” and that its actions in cells lead to activation of AMPK, a cellular energy sensor (Lee et al., 2015). AMPK is also switched on by exercise, which is the link that drew athletes in. The same paper found that MOTS-c treatment in mice prevented diet-induced obesity and insulin resistance.

Why do athletes and lifters look at MOTS-c?

Athletes look at MOTS-c for two reasons: mouse studies in which treated animals ran longer, and human studies showing that exercise raises the body’s own MOTS-c. The anti-doping view summarizes the same pitch: the US Anti-Doping Agency notes that “exercise causes MOTS-c levels to go up in humans” and that MOTS-c treatment improved physical performance in mice of all ages (USADA). USADA also observes that websites and influencers promote it as an injectable weight-loss and bodybuilding peptide. In physique terms, the appeal is endurance and conditioning plus leaning out, framed as a mitochondrial upgrade rather than a hormone.

What did the exercise-capacity studies actually measure?

The headline performance data come from one 2021 Nature Communications study in mice, and they measured treadmill and coordination tests, not sport performance in people (Reynolds et al., 2021). Evidence level in words: preclinical (mouse) results from one study, no human performance trial. In that study:

• Young mice given daily MOTS-c for two weeks did better on the rotarod (a rotating-rod test of physical capacity and coordination), but daily MOTS-c did not improve their grip strength.
• Middle-aged and old mice treated for two weeks ran longer on a treadmill with higher power output. Old treated mice ran about 2-fold longer and 2.16-fold farther than untreated old mice.
• Very old mice started on intermittent treatment late in life (three times a week) showed better physical capacity, which the authors describe as improved healthspan.

Those are real, measured results, but every one of them is a rodent outcome. The study’s single human experiment did not give anyone MOTS-c: it measured what happened to the body’s own MOTS-c when ten sedentary young men exercised on a stationary bike. Muscle MOTS-c rose 11.9-fold after exercise and stayed raised after four hours of rest, with a smaller rise in blood (Reynolds et al., 2021). That shows exercise raises MOTS-c. It does not show that injecting MOTS-c reproduces training adaptations in a person, which is the arrow the “exercise in a vial” line quietly reverses.

What do human studies of athletes and exercise show?

The human studies measure the body’s own MOTS-c in people who exercise or train; none of them gave anyone MOTS-c, and they do not agree on a simple story. The table sets out what each one measured. PeptideAgent’s MOTS-c profile summarizes the human record the same way: circulating levels that rise with exercise and a genetic variant linked to diabetes risk, with no published human treatment trial.

Human studies of the body’s own MOTS-c and exercise. None of them gave participants MOTS-c. Sources linked in the text below.

Attribute	Who was studied	What was found
Reynolds et al., 2021	10 sedentary healthy young men, one bike session	Muscle MOTS-c up 11.9-fold after exercise; smaller rise in blood
von Walden et al., 2021	30 adults randomized to endurance exercise, resistance exercise or rest	Only a trend toward higher blood MOTS-c after endurance exercise; blood levels not linked to VO2max or leg strength
Alser et al., 2022	75 professional athletes vs 30 non-athletes	Athletes had lower blood MOTS-c than sedentary controls
Domin et al., 2023	20 physically active adults (preliminary study)	Higher MOTS-c tracked with jump power and muscle mass, not with peak VO2
Feng et al., 2025	Marathon runners vs sedentary people, plus trained mice	Authors report a close association between blood MOTS-c and aerobic capacity

The details matter. In the randomized Swedish study, 45 minutes of cycling raised humanin, a related mitochondrial peptide, while “MOTS-C levels showed a trend to increase” only after endurance exercise, and resting levels were not correlated with VO2max, leg strength or muscle mitochondrial DNA (von Walden et al., 2021). A Qatar study of professional athletes found the opposite of what the marketing implies: athletes “had lower levels of MOTS-c” than sedentary controls, and levels did not differ between low/moderate and high endurance athletes (Alser et al., 2022). A small Polish study linked higher serum MOTS-c with jump force, power and muscle mass, but found “no correlation with peak VO2” (Domin et al., 2023). A 2025 study of marathon runners pointed the other way on endurance, reporting “a close association between serum MOTS-c levels and aerobic exercise capacity” (Feng et al., 2025).

Read together, these studies say MOTS-c responds to training in some way, but they disagree on direction and on whether it tracks endurance or strength. At least two (the professional-athlete study and the blood measurements in the 2021 bike study) used ELISA immunoassays, and an anti-doping lab found that ELISA readings of normal MOTS-c levels “could not be confirmed” by mass spectrometry (Knoop et al., 2019), so some of the disagreement may be measurement. None of them tells you what taking MOTS-c would do.

Is MOTS-c for endurance or for strength?

The evidence does not settle it, and one genetic finding complicates the endurance story. Some East Asian people carry a natural MOTS-c variant, K14Q, that is less biologically active. In a Japanese study, that variant was more common in sprint and power athletes (6.5%) than in controls (5.1%) and endurance athletes (2.9%), and carriers had more fast-twitch fibers and, in men, higher leg torque (Kumagai et al., 2022). In other words, the less active form went with power, not endurance. A 2024 follow-up linked the same variant in men with higher risk of sarcopenia and type 2 diabetes (Kumagai et al., 2024). These are population associations, not dosing results, but they are a reason to doubt the idea that more MOTS-c simply means better performance in every sport.

Is MOTS-c banned in sport?

Yes. The WADA Prohibited List names it directly under S4.4.1, activators of AMPK, alongside AICAR: “mitochondrial open reading frame of the 12S rRNA-c (MOTS-c)” (WADA Prohibited List). USADA confirms it is “prohibited at all times,” in and out of competition, and says a therapeutic-use exemption is highly unlikely because there is no approved therapeutic use (USADA). USADA’s advisory on the 2027 list adds that peptides in general are now named in the S0 class of non-approved substances, starting January 1, 2027 (USADA 2027 advisory).

Can MOTS-c show up on a drug test?

Yes, a detection method exists. Researchers at the German Sport University Cologne’s doping-control center built a mass-spectrometry test for MOTS-c in plasma, validated it to WADA’s laboratory standard, and reported a detection limit of 100 pg/mL; the assay also tracks four breakdown products and two oxidation products (Knoop et al., 2019). The authors wrote it was developed because monitoring possible use of synthetic MOTS-c in sport “appears advisable.” For a tested athlete, a “research use only” label changes nothing.

What are the side effects of MOTS-c?

MOTS-c’s side effects in people are largely uncharacterized, because there are no completed human trials of it. USADA lists effects reported by people who buy it online, “including increased heart rate or heart palpitations, injection site irritation, insomnia, local or generalized immune reactions, and fever,” and notes there is no data on long-term use (USADA). A 2026 Sports Medicine review of peptides used for injury and performance concludes that for unapproved peptides “rigorous human safety data are scarce, and there is potential for serious harm,” and it flags the placebo effect, amplified by social media, as a driver of perceived benefit (Mendias and Awan, 2026). Our sister site’s MOTS-c side effects guide covers the full safety record.

What does MOTS-c cost?

There is no reference price, because there is no approved MOTS-c product: the price is whatever a vendor or prescribing service sets. For an athlete, the bigger cost is not the vial. A positive test for a substance named on the Prohibited List can mean a sanction, and the outcome athletes are paying for has been measured in mice, not in people who train.

What are people saying about MOTS-c and training?

The online conversation treats MOTS-c as an energy and mitochondrial peptide more than a performance drug. In 19 posts on X that our community tracker collected between July 16 and 19, 2026, users most often described it as boosting energy and mitochondrial function; some paired it with training sessions for energy, and others mentioned it alongside pre-workout, fasting and cardio in wider routines. The most common stack was MOTS-c with SS-31, with no agreement on whether to run them together or in sequence. Some users were skeptical and described MOTS-c as part of a peptide hype cycle. These are anecdotes from one platform over four days, not evidence. The hub’s MOTS-c overview has the wider community summary.

The bottom line for athletes

The sport case for MOTS-c rests on treadmill results in mice and on the fact that exercise raises the body’s own MOTS-c. The human studies of athletes disagree with each other, no trial has measured performance in people taking it, and WADA bans it by name at all times, with a validated test in place. If you compete under an anti-doping code, it is off the table. If you do not, the honest description is an experimental peptide whose training benefits have been shown in mice. The firmest human finding here runs the other way: in the one study that measured muscle levels, a hard bike session raised the body’s own MOTS-c.

Status: Not FDA-approved; sold by some telehealth providers as a compounded prescription. An FDA advisory committee reportedly voted in July 2026 to recommend allowing pharmacies to compound it; nothing has changed yet. What this status means.

Educational information only, not medical advice. Updated October 12, 2026.