MOTS-c Compounded vs Branded: What Patients and Clinicians Need to Know

Is there a branded MOTS-c?

No. MOTS-c has no FDA-approved drug product. FDA found no product authorised by the European Medicines Agency and no USP or National Formulary monograph [1].

The name itself is informal. MOTS-c stands for mitochondrial open reading frame of the 12S rRNA-c: a 16-amino-acid peptide, molecular weight about 2174.6 g/mol, encoded in mitochondrial DNA and first reported in 2015 by Lee and colleagues in Cell Metabolism [1][8]. 'MOTS-c' is a common name, not an official drug name, and FDA treats the free base and the acetate salt as different bulk substances [1].

What 'compounded MOTS-c' actually means

Compounding is a pharmacy or physician preparing a drug for an individual patient from a bulk substance. It is not the same pathway as drug approval, and compounded drugs are not FDA-approved: FDA does not review their safety, effectiveness or quality before marketing [6].

MOTS-c is sold on websites alone and in combinations, including an IV cocktail offered by a wellness clinic, and no outsourcing facility reported compounding it from January 2017 to December 2025 [1]. Its nominated uses are insulin resistance, obesity, osteoporosis, vascular calcification, muscle and fat metabolism, and longevity, at 5 mg and 10 mg subcutaneous injections [1].

Where MOTS-c stands with FDA right now

FDA's page on bulk substances that may raise significant safety risks places MOTS-c in the 'nominated but withdrawn' table, which holds substances previously in category 2 whose nominators withdrew them. FDA's stated concerns are that it has not identified any human exposure data on drug products containing MOTS-c administered by any route, that the substance lacks important safety information, and that injectable peptides may pose immunogenicity risk because of aggregation and impurities. Removal from category 2 was not a finding that it is safe [9].

MOTS-c appears in none of the three categories on FDA's list for state-licensed pharmacies and physicians (updated 14 May 2026), and on none on FDA's list for outsourcing facilities (updated 21 March 2025). FDA's category 1 policy, under which it generally does not intend to act against compounders who meet the stated conditions, does not cover it [2][3][4].

FDA staff proposed in a July 2026 briefing document that neither the free base nor the acetate be added to the pharmacy bulks list. The reasons given were that MOTS-c is not well characterised (inconsistent naming; no impurity, aggregate or endotoxin data), that its use in compounding is unknown, that there are no human safety or effectiveness data and no animal toxicity studies, and that FDA-approved treatments exist for obesity and osteoporosis, two of the nominated uses [1].

On 23 July 2026 the Pharmacy Compounding Advisory Committee voted in favour of adding MOTS-c to the bulks list, against the staff recommendation. That vote is advice only and is not binding. MOTS-c is not on the list, and adding it takes formal rulemaking [5][6].

HHS filed a draft enforcement-discretion policy on 28 October 2026 (Federal Register document 2026-22192, publication scheduled for 30 October 2026) that names MOTS-c among six peptides. It covers MOTS-c acetate given by subcutaneous or intramuscular injection, and says HHS does not intend to take enforcement action against a state-licensed pharmacy, federal facility or licensed physician compounding with it when the conditions are met, such as a single active ingredient, a patient-specific prescription, an FDA-registered manufacturer with a certificate of analysis, and a label reading 'This is a compounded drug product. Not for resale.' [6][10].

The draft is not an approval and does not place MOTS-c on any list. The notice says it does not establish any rights for any person and is not binding on HHS or the public, and HHS may revisit it, for example if a safety signal or product quality issue arises [6].

What human evidence supports either version?

None for injected MOTS-c. The pharmacology comes from cells and rodents. In mice, injected MOTS-c reduced weight gain on a high-fat diet (about 20% lower body weight after 8 weeks at 0.5 mg/kg/day intraperitoneally), improved insulin sensitivity and exercise performance, and in one study a late-life schedule (15 mg/kg three times weekly from 23.5 months of age) lengthened median lifespan from 912 to 970 days [1][8][11]. Effects appear to involve AMPK signalling and reduced one-carbon (folate) metabolism, but FDA says the molecular targets are unknown and no dose-response relationships were assessed [1][8].

The human studies measured the body's own MOTS-c, not an injected product. In Reynolds and colleagues' 2021 Nature Communications work, exercise induced endogenous MOTS-c expression in skeletal muscle and in circulation in humans, while in mice injected MOTS-c improved physical performance and late-life intermittent treatment increased physical capacity and healthspan [11]. In a randomised trial by von Walden and colleagues published the same year, 30 healthy adults were assigned to endurance exercise (n=10), resistance exercise (n=10) or control (n=10); circulating humanin rose after endurance exercise, while MOTS-c showed only a trend to increase, and plasma MOTS-c was not related to fitness [12].

A separate 2015 paper in Aging Cell proposed that the m.1382A>C variant in the MOTS-c gene, found in Northeast Asian populations, might help explain Japanese longevity. It is a hypothesis paper about a gene variant, not a treatment trial [13].

Dose: there is no approved dose

There is no approved dose and no human dosing study of administered MOTS-c [1]. The nominated products were 5 mg and 10 mg subcutaneous injections [1]. The rodent doses used in experiments, 0.5 to 15 mg/kg, cannot be converted into human doses [1]. Seller schedules should not be presented as established dosing.

Safety: what is known and what is not

FDA's adverse-event database searches through 9 March 2025 retrieved no MOTS-c reports [1]. That is an absence of reports, not a safety finding. FDA found no clinical study in which MOTS-c was administered to people, no human exposure data by any route, and no animal toxicity studies, so safety in humans is unknown [1]. FDA says injectable peptides may pose an immunogenicity risk because of aggregation and peptide-related impurities. MOTS-c has no immunogenicity data [1].

There are also no pharmacokinetic data in humans or in live animals. The only kinetic observation is that MOTS-c is quickly broken down in human blood in vitro, which raises the question of whether injecting it can produce active levels in people [1].

Athletes: MOTS-c is prohibited at all times

WADA names MOTS-c in section S4.4.1 of its Prohibited List, among metabolic modulators listed as activators of AMP-activated protein kinase, alongside AICAR. It is prohibited at all times, in and out of competition, and S4.4 substances are non-Specified Substances [7]. It is on the 2026 List, in force since 1 January 2026, and remains on the 2027 List; FDA notes it was already on the 2024 List [7][14][1].

What would change this picture

A manufacturer filing and obtaining an approved application, or FDA completing rulemaking that actually adds MOTS-c to the pharmacy bulks list, would change the regulatory answer. Neither has happened. An HHS draft policy is a statement of enforcement intent that the notice itself says is non-binding [6]. Until one of those changes, the compounded-versus-branded comparison has only one side.