MOTS-c vs Glutathione
Sold as a way to get the benefits of exercise without training. Mice given it stayed lean and ran longer, but it has not been tested in people. It is sold as an antioxidant booster, for skin lightening drips and for detox. One small trial showed slight lightening at two skin sites, and trials for other uses failed.
Glutathione has the stronger evidence, grade B (some human evidence) against grade C for MOTS-c. Neither is FDA approved.
Evidence
CAnimal and cell studies
BSome human evidence
Human studies cited
Animal or cell studies cited
Why the grade
The efficacy data are in mice: the 2015 discovery paper showing protection from diet-induced obesity and insulin resistance, and a 2021 paper showing better physical performance in young and old mice. The only human data measure the body's own MOTS-c rising in muscle and blood after exercise. No human has received MOTS-c in a published trial, so C.
For skin lightening, the use glutathione is most often sold for, there is one randomised placebo-controlled trial of oral glutathione in 60 healthy students that found a small drop in melanin index at two of six skin sites. The larger trials in hand were for other purposes: a 153-patient inhaled trial in cystic fibrosis that missed its primary endpoint, a 54-adult trial showing oral glutathione raises blood levels, and a 21-patient Parkinson's pilot. No trial of intravenous glutathione for skin exists.
FDA
Not approved
Not approved by the FDA for any use and sold as a research chemical. MOTS-c was placed in Category 2 (significant safety risk) in 2023; the nomination was withdrawn, the FDA removed it from that category in April 2026, and the Pharmacy Compounding Advisory Committee voted in July 2026 to recommend it for the compounding list. On 28 October 2026 HHS issued an enforcement discretion policy covering injectable MOTS-c acetate compounded by licensed pharmacies and physicians for named patients under sourcing, testing, labeling and reporting conditions. That is not an approval. It is also on the 2026 WADA Prohibited List.
Not approved
Glutathione is not approved by the FDA as a drug for any indication. Oral glutathione is sold as a dietary supplement, intravenous and inhaled forms are made by compounding pharmacies, and glutathione sits in Category 1 of the FDA's list of nominated compounding substances, meaning it may be compounded while the agency evaluates it. In August 2026 the agency warned compounders not to use supplement grade glutathione in injectables after a cluster of adverse events.
Sold for
MOTS-c is sold as an 'exercise mimetic', a mitochondrial peptide said to burn fat, improve insulin sensitivity, and boost endurance the way training does.
Glutathione is sold as a master antioxidant, for skin whitening by intravenous drip, for detox and for Parkinson's disease.
Studies say
Mice given MOTS-c resisted obesity and ran longer, and humans make more of it after exercise, but no trial has given it to people, so the evidence is grade C.
Oral glutathione does raise body stores and produced a modest, site-specific lightening in one small trial, while inhaled glutathione failed in cystic fibrosis and intravenous glutathione showed no clear benefit in a Parkinson's pilot, so the grade is B for the skin claim and lower for the others.
Class
Mitochondrial-derived peptide
Antioxidant tripeptide
Route
Injection
Several routes