MOTS-c half-life: what has been measured?

Evidence limits

What is the half-life of MOTS-c?

A test-tube result is not a whole-body half-life. Blood in a dish has no kidneys, no liver and no tissues taking up the peptide. FDA's reading of the Knoop test-tube study, which had no participants, was that MOTS-c is quickly hydrolysed (split by water into smaller pieces) in human blood, and it wrote that it remains to be determined whether MOTS-c supplied to humans can generate pharmacologically active concentrations over time (FDA briefing document, 11 May 2026).

Measuring MOTS-c in blood is itself difficult. In a reference group of 20 healthy people, a commercial antibody test (ELISA) reported plasma MOTS-c levels of 45.9 to 218.5 ng/mL, and a mass-spectrometry method with a lower limit of detection of 100 pg/mL could not confirm them, a comparison of two assays in one laboratory that leaves the true levels unresolved (Knoop et al., Rapid Communications in Mass Spectrometry, 2019). Any half-life figure therefore depends on the assay behind it. The MOTS-c research guide covers the first papers on this peptide in plain English.

Is there an official study of the MOTS-c half-life?

The sources checked on 14 October 2026 did not include an official or regulator-published study of MOTS-c's half-life. The FDA briefing document of 11 May 2026 states that the nominator did not submit, and FDA did not identify, in-vivo pharmacokinetic or toxicokinetic studies. A ClinicalTrials.gov search for MOTS-c returned nine records on that date, and the one record that lists a MOTS-c intervention, NCT07505745, a Phase 2a trial with 120 participants planned, names insulin sensitivity and adverse events as primary outcomes and lists no pharmacokinetic outcome. A 2026 study in isolated rat hearts ends by calling for further pharmacokinetic studies before translational application, and its abstract reports no half-life value (Santhanam et al., Naunyn-Schmiedeberg's Archives of Pharmacology, 2026).

A PubMed search of titles and abstracts for MOTS-c with the words pharmacokinetic or half-life returned three records on 14 October 2026. They are a 2026 review of MOTS-c in sepsis-related heart injury that lists pharmacokinetic and biodistribution issues among its open questions (Zhao et al., European Journal of Pharmacology, 2026), the rat heart study (Santhanam et al., 2026) and a 2023 mouse colitis study of a modified MOTS-c (Jiang et al., 2023). The abstracts of those three records did not report a half-life value for MOTS-c in an animal or a person, and a three-record search of one database does not rule out a value reported elsewhere.

Half-life figures quoted on commercial websites could not be matched to a measurement in PubMed, ClinicalTrials.gov or the FDA briefing document searched on 14 October 2026. A half-life figure has a meaning only together with its species, its sample type and its assay, and with whether it comes from MOTS-c itself or from a modified form.

Laboratory paperwork answers a different question from pharmacokinetics. A certificate of analysis records identity and purity tests on one batch, as how to read a certificate of analysis explains, and it says nothing about how long a peptide stays in the body. The site catalogue lists MOTS-C reference material as freeze-dried laboratory stock.

How long do MOTS-c levels stay raised after exercise?

In 10 sedentary healthy young men who cycled on a stationary bicycle, blood MOTS-c measured by ELISA rose about 1.6-fold during exercise and 1.5-fold right after, then returned to baseline after 4 hours of rest, while muscle MOTS-c rose about 11.9-fold and was still elevated after the 4-hour rest, although it trended back toward baseline; this is one small group and the study measured the body's own peptide, not MOTS-c given to anyone (Reynolds et al., Nature Communications, 2021). In a second trial of 30 volunteers randomised to endurance exercise, resistance exercise or no exercise (10 per group), blood sampled before and at 30 minutes and 3 hours showed only a trend toward higher MOTS-c after endurance exercise, again a measurement of the body's own peptide in a small trial (von Walden et al., Journal of Applied Physiology, 2021).

These numbers describe the peptide your own cells make, in a few snapshots. They are not a half-life, because a half-life needs repeated samples after a known amount enters the blood, and the body keeps making MOTS-c while it is cleared. The retatrutide pharmacokinetics page shows what a measured half-life looks like when a trial does that work.

What time courses have studies reported for MOTS-c effects?

The sources read report time courses only in animals and in one analog trial, so no onset time in people was found in them. In normal-diet mice, Lee et al. saw modest drops in body weight, food intake and blood glucose after 4 days of treatment, a mouse result that does not establish a timing or an effect in people (Cell Metabolism, 2015). In young mice on a high-fat diet, Reynolds et al. saw better treadmill running after 10 days in the study's higher-amount group but not after 7 days, a mouse experiment that does not establish onset or performance effects in people (Nature Communications, 2021). In 20 adults with fatty liver disease (11 on the analog CB4211 and 9 on placebo), the sponsor reported lower ALT and AST on CB4211 than on placebo after four weeks, a company report on a different molecule with no results posted on the registry (CohBar annual report, 29 March 2022). The registered Phase 2a trial of MOTS-c, with 120 participants planned, lists insulin sensitivity at 12 weeks as its primary outcome and has posted no results (ClinicalTrials.gov NCT07505745, checked 14 October 2026).

Reynolds et al. also note that 7 days of MOTS-c treatment improved skeletal muscle insulin sensitivity in young and older mice on a high-fat diet, an effect they had reported earlier; it is a mouse result that differs in timing from the treadmill result above and does not establish human timing or insulin-sensitivity effects (Nature Communications, 2021).

A time in mice does not convert into a time in people. The mouse studies used animals on controlled diets, and the passages read for this page did not report how fast the peptide cleared from blood.

How long do the effects of MOTS-c last in studies?

The sources read did not report how long MOTS-c effects last after treatment stops, in people or in animals. In male mice started on late-life treatment at about 24 months of age, Reynolds et al. measured physical tests, blood glucose, fat mass and survival toward the end of life, not the persistence of any effect after stopping, so the mouse study does not answer the question (Nature Communications, 2021). The registry record of the CB4211 analog trial, with 88 participants, lists blood sampling time frames of 24 hours, 7 days and 28 days and posts no results, so the trial record does not answer it either (ClinicalTrials.gov NCT03998514, checked 14 October 2026).

In male mice started on late-life treatment, the authors reported a trend toward a 6.4% longer median lifespan and a 7.0% longer maximum lifespan, with a hazard ratio of 0.654 and an overall-curve P value of 0.23, and wrote that larger cohorts are needed; the result concerns mice and does not establish lifespan effects in people (Reynolds et al., Nature Communications, 2021).

Do changes to MOTS-c change how long it lasts?

In a mouse colitis study, a form joined to a cell-penetrating peptide tail showed a longer half-life than MOTS-c in laboratory experiments and improved colitis in mice; the abstract gives no half-life value and the work does not concern people (Jiang et al., European Journal of Pharmacology, 2023). In a 2026 study of R13A-MOTS-c, a form that swaps one amino acid, the authors reported better cellular uptake in cell experiments and less lung injury in irradiated mice; the abstract gives no half-life value and the work does not concern people (Zhang et al., Redox Biology, 2026).

CB4211 is a separate case. Its sponsor described it as a novel and improved analog of MOTS-c (CohBar annual report, 29 March 2022), and the registry record of its 88-participant trial lists the terminal elimination half-life of CB4211 as a secondary outcome (ClinicalTrials.gov NCT03998514). The registry record and the annual report read for this page give no half-life value, and results for a modified molecule do not carry over to MOTS-c itself. What the studies found covers the CB4211 trial outcomes.