MOTS-c dosage chart: what mice received and why no human dose exists

Nobody knows the right dose of MOTS-c for a person, because no human trial of MOTS-c has published one. The only numbers on record for MOTS-c are the doses injected into mice, and they appear below with the dose of a related but different molecule tested in one small human study. This is a chart of what studies used, and it is not a schedule for anyone to follow. MOTS-c is not FDA-approved.

What the mouse studies used

Both key papers come from the University of Southern California group that discovered MOTS-c. The methods of the 2015 paper state that MOTS-c “was injected daily via intraperitoneal injections in all in vivo experiments”, meaning into the abdominal cavity.

The doses are written as mg/kg, milligrams of peptide per kilogram of mouse body weight. They span a thirtyfold range. One 2021 experiment compared 5 with 15 mg/kg and found only the higher dose improved running, and FDA’s 2026 review concluded that the animal studies “have not evaluated the dose-response relationships for the effects of MOTS-c in vivo.”

The only human dose on record is for a different molecule

CB4211 is not the MOTS-c sold online. Its dose tells you nothing reliable about MOTS-c, and its phase 1 study had to be interrupted because some of the injected drug stayed deposited under the skin. The phase 2a trial is the first registered test of MOTS-c itself, and it has no results. Until it reports, the dose it used remains unpublished.

Why mouse mg/kg does not become a human dose

It is tempting to do the math on a mouse dose, and any number you get would be meaningless. We do not publish one, for three reasons.

Mice are not small humans. Drug clearance and metabolic rate do not scale with body weight, so multiplying a mouse dose by a person’s weight is wrong from the first step. FDA’s 2005 guidance adjusts for body surface area, and that adjustment is only one early step in a larger process that ends with a heavy safety margin.

The method is for trials, not treatment. FDA’s approach exists to choose a cautious starting dose for a phase 1 trial, which then escalates under monitoring. It assumes the animal dose came from formal toxicology studies that found no harm. FDA’s 2026 briefing document says there is “no available nonclinical data to inform safety considerations” for the uses it reviewed. The method’s starting point is missing.

Routes differ. The mice received injections into the abdominal cavity. People who use MOTS-c inject it under the skin. Nobody has published how much MOTS-c reaches the blood from an injection under the skin, how long it lasts, or whether it reaches active levels. FDA’s reviewers wrote that “it remains to be determined whether exogenous administration of MOTS-c to humans can generate pharmacologically active concentrations of the peptide over time.”

Per day, per week, cycles and missed doses

These are the questions most people arrive with, and each has the same answer.

• Per day or per week: no amount has been tested in a published human study of MOTS-c.
• Time of day and food: never studied in people.
• Cycles and breaks: no study supports any on-and-off pattern. The mouse schedules were chosen for experiments, not to find a human regimen.
• Where to inject: the MOTS-MET trial uses injection under the skin, and the HHS policy names subcutaneous or intramuscular routes. Neither publishes a body site or an amount.
• Missed doses: a missed-dose rule comes from a drug label, and MOTS-c has none.

What online protocols claim

Clinic menus, forums and seller pages describe MOTS-c schedules in milligrams, injected under the skin. No clinical study supports any of them. We mention them only because readers will meet them elsewhere, and we do not reproduce the numbers. None has been tested against placebo, and none was derived from the published mouse data by any validated method. Calling something a “protocol” or printing it as a PDF does not make it one.

What the HHS policy says about dose

Nothing. As of November 2, 2026, HHS says it does not intend to take enforcement action against a state-licensed pharmacy, federal facility or licensed physician compounding MOTS-c acetate for subcutaneous or intramuscular injection, if ten conditions are met, until a final rule addresses it. The conditions cover the ingredient’s identity and testing, a patient-specific prescription, a single active ingredient, labeling and adverse event reporting. HHS’s document mentions a “compounded regimen” in passing and does not state one.

So a compounded prescription would rest on the prescriber’s judgment with no human MOTS-c dose data behind it. MOTS-c is still not on the 503A bulks list, no rule has been proposed, and FDA has reviewed no compounded product for safety, effectiveness or quality. The notice says the policy is not binding, comments run until November 13, 2026, HHS may revisit it if a safety signal or quality problem appears, it covers 503A compounding only, and states can be stricter.

The syringe arithmetic

MOTS-c sold online is a freeze-dried powder that has to be mixed with bacteriostatic water before injection (see how to reconstitute). If a pharmacy has dispensed a compounded vial, its label gives the concentration and the prescriber gives the amount. The unit marks on a U-100 insulin syringe measure volume, not peptide: 100 units is 1 mL, so 1 unit is 0.01 mL. How much peptide sits in each unit depends entirely on how much water went in.

A worked example with a 10 mg vial:

• 10 mg = 10,000 mcg (micrograms). That is the total in the vial no matter how much water is added.
• Add 2 mL of water: 10 mg divided by 2 mL = 5 mg per mL.
• 5 mg per mL divided by 100 units = 0.05 mg, or 50 mcg, per unit.

The same arithmetic at two example vial sizes. These are illustrations, and the water volumes are not recommendations:

We leave out dose columns on purpose, because no MOTS-c dose exists to put in them. The reconstitution calculator below does the same math for any vial and any volume of water, and the mg/mL to units converter works the other way round.

Where the arithmetic goes wrong:

• Mixing up mg and mcg. 1 mg is 1,000 mcg. MOTS-c amounts are usually written in mg, while many other peptides are written in mcg, so copying a table from another peptide can be off by a factor of 1,000.
• Treating units as milligrams. A unit is a hundredth of a milliliter. It holds whatever the concentration says it holds.
• Forgetting that the water changes everything. A table made for a vial mixed with 1 mL is wrong for a vial mixed with 2 mL.
• Overfilling a small syringe. At low concentrations, a few milligrams can exceed the 30 or 50 units a small insulin syringe holds.
• Trusting the label. Research-grade vials carry no FDA-verified content. FDA’s briefing document notes that different salts and even different molecules are sold under the name MOTS-c.

Research vials are a separate matter

Products sold “for research use only” are not legal to use on people, and the HHS policy gives them nothing. Those vials fall under 21 CFR 312.160, which allows shipment only for tests in laboratory animals or in vitro, with a label reading “Not for use in humans.” The MOTS-c side effects page covers what is known about safety, and the FDA status tracker follows the rulemaking.