No published study has measured the MOTS-c half-life in people. That is the whole honest answer, and it is worth hearing before anyone quotes you a number.
Half-life is a plain idea: how long your body takes to clear half of a dose. For most injectable medicines it is a measured figure sitting in a trial report, and it is what tells a prescriber how often to give something. For MOTS-c, that measurement has never been made and published in humans.
What does exist is still worth knowing. The MOTS-c your own body makes rises and falls over hours. A lab-made cousin of it went into a human trial that listed half-life as something it would measure — and the result was never released. Everything else is somebody's inference.
What we actually know about the MOTS-c half-life
MOTS-c is a very short peptide, sixteen amino acids long, and unusual in that your mitochondria encode it themselves rather than your main DNA. Researchers at the University of Southern California described it in 2015 — they found it tucked inside the mitochondrial 12S rRNA gene — and showed that giving it to mice improved insulin sensitivity and blunted weight gain on a high-fat diet (Cell Metabolism, 2015).
Peptides that short usually do not last. Enzymes in the blood take them apart and the kidneys clear the pieces. A 2026 review of therapeutic peptides describes the general pattern: many injected peptides are gone within minutes to hours, and the ones that stick around do so because a chemist deliberately built in something to slow them down (International Journal of Molecular Sciences, 2026).
That same review is blunt about MOTS-c in particular — the evidence is almost entirely preclinical, with no human trials characterising safety or dosing. A 2022 review from the lab that discovered these peptides calls circulating MOTS-c "relatively short" without putting a number on it, and notes that humanin, the first mitochondrial-derived peptide ever found, clears with a half-life of roughly 20 minutes (Journal of Clinical Investigation, 2022).
| What people ask | Where the evidence stands |
|---|---|
| A human half-life for MOTS-c | No published measurement |
| An animal half-life for MOTS-c | Not established; reviews describe it only as "relatively short" |
| A human half-life for a MOTS-c analogue | Measured in a Phase 1 trial, results never posted |
| How long exercise raises your own MOTS-c | Back to baseline in about four hours |
The MOTS-c your body makes comes and goes in hours
The one place anyone can watch MOTS-c move in real time is exercise, because activity pushes your own levels up.
In a 2021 study, ten sedentary healthy young men rode a stationary bike and had blood and muscle sampled around the ride. MOTS-c in muscle rose about twelvefold. In blood the rise was smaller — roughly one and a half times where it started — and it was back to baseline after four hours of rest (Nature Communications, 2021).
As of September 6, 2026, the day this article was written, the most recent human measurements come from a study published on 25 June 2026 in Experimental Physiology. It compared adults with cerebral palsy against typically developing adults and adolescents after 45 minutes of running. Resting blood MOTS-c sat around 170 to 190 pg/mL in every group — picograms, trillionths of a gram — and an hour after running it had risen by a small but statistically significant amount in all three groups (Experimental Physiology, 2026).
Two things follow from that. Your own MOTS-c behaves like a signal that comes and goes across hours, not days. And it says nothing direct about an injected dose, which starts from a different place and arrives by a different route.
The one human trial that measured it never told us
There is exactly one human study that set out to measure this, and it did not study MOTS-c.
CB4211 is a modified version of the peptide, built by a company called CohBar. Its Phase 1a/1b trial enrolled 88 people, gave single and repeated injections under the skin to healthy volunteers and to people with fatty liver disease, and listed "apparent blood/plasma terminal elimination half life" among the things it would measure. The trial finished on 19 April 2021. No results have ever been posted to the public registry (ClinicalTrials.gov NCT03998514).
So the nearest thing to a human half-life for a MOTS-c-like molecule exists somewhere as data and has never been shared. And CB4211 was changed on purpose from the natural sequence, which means that even if the number surfaced tomorrow it would describe the analogue and not MOTS-c.
What a measured number looks like, for comparison
SS-31, also called elamipretide, is another peptide aimed at mitochondria, and it has been through Phase 1, 2 and 3 trials in people — which is exactly why published human figures exist for it and not for MOTS-c. Same idea, very different depth of evidence. If you want the fuller picture there, what SS-31 has actually been studied for covers it.
None of that argues for or against either compound. It is a reason to be wary of anyone who hands you a MOTS-c half-life with a decimal point in it.
Why the injection schedules online are not evidence
Search for how often to inject and you will find schedules stated with total confidence — daily, every other day, five days on and two off. Trace them back and they end in one of two places: rodent experiments, or a seller's page.
The rodent protocols are real research. They were also designed around mice, which clear peptides at their own rate and received them by a route people do not use. In the 2021 study above, the older mice were treated three times a week.
There is a second confusion worth naming. How long a molecule stays in your blood and how long its effect lasts are separate questions. MOTS-c moves into the cell nucleus and changes which genes are switched on, and a change like that can outlast the molecule that triggered it by a wide margin. Detectability and duration of effect do not have to match — the same trap that muddles the BPC-157 half-life conversation.
It is also why there is no standard MOTS-c dose, and why what is known about MOTS-c side effects is thinner than most sites let on.
Researchers are working on the delivery problem rather than waiting for it to solve itself. One 2026 group swapped a single amino acid in the sequence to make the peptide easier for cells to take up, then tested it in mice (Redox Biology, 2026). That work is early and it is in animals, but it tells you what the field considers the real obstacle.
What this means if you are considering it
MOTS-c is not FDA-approved, and neither is any compounded version of it. That describes the regulatory record rather than delivering a verdict on whether it suits you — a licensed provider can still prescribe a compounded formulation, and that decision belongs to you and your doctor.
What the missing number does mean is that any schedule you are given is a clinical judgement rather than arithmetic off a label. A prescriber works from the published animal and human research, your history, and what you are actually trying to address, then adjusts. At Promise a licensed provider reviews every request, and not everyone qualifies.
If the gap in the evidence bothers you, that instinct is worth trusting rather than talking yourself out of — and it is a fair thing to raise before you start.