MOTS-c

MOTS-c is a chain of 16 amino acids ^[6]. Amino acids are the building blocks of proteins. The body makes small amounts of MOTS-c from genes inside mitochondria, the parts of a cell that turn food into energy ^{[13] [18]}. It is found in the blood of people and rodents ^[6]. Scientists first described it in 2015 ^{[6] [13]}. The MOTS-c that is sold is made in a lab ^[6].

MOTS-c is part of no FDA-approved drug and has no official quality standard ^[6]. It is sold in two forms, a free base and an acetate salt, and FDA treats them as two different substances ^[6]. Websites promote it for energy, weight loss, blood sugar, exercise and slower aging ^[6]. Sport rules ban it, and labs test athletes for it ^{[6] [17]}.

MOTS-c is in limbo: FDA lists it among the Category 2 substances whose nominations were withdrawn, and it has not added it to Category 1 ^{[1] [2]}. That is not approval, and it does not make compounding lawful. FDA's meeting notice lists obesity and osteoporosis as the uses it reviewed, but websites promote MOTS-c for energy, exercise and slower aging ^{[4] [6]}. Checked 23 October 2026.

Category 2 is FDA's list of substances that may present significant safety risks. Category 1 is the list of substances pharmacies may use while FDA reviews them ^[3]. The pharmacy that nominated MOTS-c pulled its nomination, so it came off Category 2 ^{[1] [6]}. FDA then reviewed it on its own. FDA's scientists found no study of MOTS-c in people and advised against adding it to the list ^{[6] [8]}.

On 23 July 2026, FDA's Pharmacy Compounding Advisory Committee met on MOTS-c ^{[4] [5] [7]}. News and legal reports say it voted 7 to 5, with 2 members abstaining, to recommend adding MOTS-c to the list ^{[10] [11] [20]}. FDA's meeting page does not show the vote ^[5]. A committee vote is only advice ^[11]. FDA decides by writing a rule, after public comment ^{[10] [11]}.

Until then, a pharmacy that makes MOTS-c is outside federal law ^{[3] [10]}. Selling it for people to use is also illegal, even when the label says it is for research only ^[9].

The evidence grade is animal-only: the studies that show an effect used mice or rat cells, and FDA found no study that gave MOTS-c to people ^[6]. FDA adds that these studies did not test how the effect changes with the amount given ^[6].

Weight and blood sugar: in mice fed a fatty diet, MOTS-c shots limited weight gain and insulin resistance ^{[6] [13]}. Insulin resistance means the body responds poorly to insulin, the hormone that controls blood sugar. In female mice whose ovaries were removed, MOTS-c limited weight gain and fat build-up ^[15]. In young, middle-aged and old mice, MOTS-c helped them run longer. Very old mice given it late in life stayed fit longer and lived a little longer ^{[6] [14]}.

Bone: the evidence for osteoporosis, a disease that thins the bones, is thinner still. In a lab dish, MOTS-c pushed rat stem cells to become bone-making cells ^[16]. In mice, shots at the top of the skull limited bone loss caused by plastic particles ^[6].

Studies in people have only measured the MOTS-c the body makes on its own. Exercise raised it ^[14]. A 2024 review found lower natural levels in people with diabetes and higher levels in people with obesity ^[19]. These studies gave MOTS-c to nobody, so they are not evidence that taking it helps ^{[6] [19]}. A review by the team that found MOTS-c calls it a signal that controls muscle and fat, based on lab and animal work ^[18].

There is no legal way to get MOTS-c in the US today ^[6]. No approved drug contains it, and Europe's drug agency lists no approved product with it ^[6]. A pharmacy may use a substance with no official quality standard only if it is in an approved drug or on the federal list. MOTS-c is neither ^{[3] [6]}. That could change if FDA adds it by writing a rule after the committee vote ^{[10] [11]}.

FDA found no clinical study of MOTS-c in people ^[6]. Any open trial that gives MOTS-c would appear in the trials block below, with the date the official registry was last checked. FDA notes that approved drugs already exist for obesity and for osteoporosis ^[6].

People who use MOTS-c get it in three main ways ^[6]. The first is websites that sell it alone or mixed with other substances ^[6]. Peptides sold this way often carry a label saying they are for research use only ^[21]. FDA says that label does not make it legal to sell a drug meant for people ^{[9] [12]}. The second is pharmacies. One clinic says it gets MOTS-c from compounding pharmacies, though no outsourcing facility reported making it from 2017 to 2025 ^[6]. The third is clinics. One wellness clinic offers a drip into a vein that contains MOTS-c, without saying what else is in it ^[6].

In all three, nobody checks what is in the product the way FDA checks an approved drug. FDA found no test results for impurities, clumps or germ toxins in MOTS-c powder ^[6]. FDA found no reports of harm from MOTS-c in its files. FDA says that does not show MOTS-c is free of harm, because pharmacies seldom report problems ^{[6] [8]}.