MOTS-c Dosage and Side Effects: What Humans Have Actually Taken

The short answer: there is no validated human dose of MOTS-c. No trial of MOTS-c itself has reported results in people. The dosing numbers that circulate online are scaled up from mouse experiments, and the only human dosing on record belongs to a modified MOTS-c analog called CB4211, given at 25 mg a day for four weeks in a 20-person study⁴. Side-effect data for MOTS-c itself does not exist in humans; FDA has stated it identified no human exposure data for it⁷.

This page lays out where the circulated numbers come from, what the one analog study found, which side effects are documented versus assumed, and where MOTS-c stands legally after the July 2026 FDA advisory vote. It is not dosing advice, because there is no evidence-based dose to give.

Where the circulated protocols come from

MOTS-c is a 16-amino-acid peptide encoded in mitochondrial DNA. Almost everything sold about it traces back to two mouse papers.

The 2015 discovery paper. Researchers at USC reported that MOTS-c improved insulin sensitivity and blunted diet-induced weight gain in mice¹. The doses were given by injection into the abdominal cavity, not under the skin, and they were weight-based: 0.5 mg/kg a day in the diet-induced obesity experiments and 5 mg/kg a day in the insulin-sensitivity and glucose work.

The 2021 exercise paper. The same research line showed MOTS-c rises with exercise in humans and improved treadmill performance in mice². The mice received 5 or 15 mg/kg a day for two weeks, and older mice got 15 mg/kg three times a week in the late-life experiments that improved physical capacity.

The human part of that paper measured something different. It found that exercise raises the body's own MOTS-c in muscle and blood². That tells you MOTS-c is part of the normal response to training. It does not tell you how much injected MOTS-c, if any, adds to it, and no study has compared the two.

Those mg/kg figures cannot be copied onto a person. FDA's own method for translating an animal dose to a human starting point divides a mouse mg/kg dose by 12.3 to account for body surface area, and that method is meant for picking a cautious first dose in a supervised trial, not a treatment dose³. Run the three mouse doses through it for a 70 kg (154 lb) adult and you get roughly 2.8 mg, 28 mg and 85 mg a day. That is a thirtyfold spread before you account for the different injection route, the daily schedule, or the fact that mice and people clear peptides differently.

Vendor protocols that quote a few milligrams per injection, a few times a week, sit at the bottom of that range or below it. Nobody has measured whether that amount does anything in a human body.

The analog that reached humans: CB4211

CB4211 is a modified version of MOTS-c developed by the biotech company CohBar. It is the only MOTS-c-family peptide with completed human dosing on record.

• •The trial: a phase 1a/1b study registered as NCT03998514, completed in April 2021, with 88 participants enrolled across single-dose, 7-day and 28-day arms, all by injection under the skin⁵.
• •The phase 1b part: 20 adults with obesity and fatty liver disease, randomized and blinded, received 25 mg of CB4211 once a day for four weeks or placebo⁴.
• •The results: the company reported lower liver enzymes and glucose than placebo and "a trend towards lower body weight," not a significant weight loss⁴.
• •The side effects: no serious adverse events, and the only adverse events in more than 10% of treated subjects were "transient and generally mild to moderate injection site reactions"⁴.

Two cautions. CB4211 is an engineered analog, not the MOTS-c sold in vials, so its dose and safety profile do not transfer automatically. And these results come from a company press release, not a peer-reviewed paper.

A placebo-controlled phase 2a trial of MOTS-c itself, in adults with prediabetes and overweight, began enrolling in February 2026 (NCT07505745). It gives a "fixed dose once daily for 12 weeks" by injection and does not publish the dose. Its primary results are not expected before 2027⁶.

Side effects: reported versus theoretical

Because no MOTS-c trial has published human results, every side-effect claim falls into one of two buckets.

Reported, in the analog: injection site reactions, mostly mild and short-lived, were the only common adverse event in the CB4211 study⁴. Four weeks in 20 people cannot detect rare or slow-building harms.

Theoretical, for MOTS-c itself:

• •Immune reactions. FDA's compounding page lists MOTS-c as a substance that "may pose significant risk for immunogenicity," meaning the body could form antibodies against it, and notes it has no human exposure data to judge by⁷.
• •Blood sugar effects. Every mouse study was designed to move glucose metabolism¹. Anyone on diabetes medication is the obvious group to ask a clinician about first.
• •Product quality. Vials sold for "research use" carry no guarantee of identity, purity, sterility or dose, which is a separate risk from the molecule itself.

So if a list of MOTS-c side effects reads as if it came from a trial, with symptoms and percentages, ask which trial. None has reported.

Legal status after the July 2026 vote

On July 23, 2026, FDA's Pharmacy Compounding Advisory Committee voted 7 to 5 with two abstentions to recommend MOTS-c for the list of bulk substances that pharmacies may compound, the narrowest favorable margin of the meeting¹⁰¹¹. FDA put two uses before the committee, obesity and osteoporosis⁸, not endurance or energy. The nomination had been withdrawn by its nominator before the meeting, and FDA presented it anyway⁹.

What that vote did not do:

• •It did not list MOTS-c. The list in federal regulation still holds six substances, none of them peptides¹². Adding one takes a proposed rule, public comment and a final rule.
• •No rulemaking has started. A search of the Federal Register for 503A bulk-substance actions in 2026 returns notices only, with no proposed rule¹⁴.
• •It did not change sport. MOTS-c has no approval for human use anywhere, which places it in WADA's S0 class, prohibited at all times¹³.

The full story of the vote, including FDA's own reviewers recommending against it, is in MOTS-c FDA status. The live position of every peptide is on the peptide regulatory tracker.

What to ask a prescriber who offers it

Some telehealth menus list MOTS-c anyway, and the prices vary more than the evidence does. Live Vital lists MOTS-c at $149 a month, but some of its "monthly" figures are ten-week protocols divided by three. Telos Rx shows MOTS-c "as low as" $116, and that floor is a 12-month-plan rate with a re-billing clause if you leave early. Pepti charges $339 per 28-day cycle, which works out to thirteen charges a year. ElitePhysiqMD prices it at $337.50 a month, and that figure already includes a subscription discount. NEUVÉ Health lists it at $245, on a site that gives three different answers about what its prices cover.

Before paying any of them, ask four questions:

1. 1.Which pharmacy compounds it, and on what legal basis? MOTS-c is not on the 503A list, so "a licensed pharmacy" is not a full answer.
2. 2.What dose, and where did that number come from? If the answer is a mouse study or "our standard protocol," you now know what that means.
3. 3.What will you monitor? A clinician prescribing a metabolic peptide should be able to say whether glucose will be checked.
4. 4.Are you a tested athlete? If so, the answer is already no.

The bottom line

MOTS-c has a real research story in mice and an exercise link in people², but no human dose has been validated. The closest human data is 25 mg a day of a modified analog for four weeks, with injection site reactions as the main side effect⁴. The first proper MOTS-c trial will not report before 2027⁶.

If what you want is a peptide a clinician can lawfully prescribe and a licensed pharmacy can fill today, the established route in this space is the GH-releasing family, sermorelin and its relatives, compared provider by provider in our recovery peptide rankings. For whether MOTS-c does anything for training, see MOTS-c for endurance: the evidence.