Body composition
Does it improve endurance or work capacity?
Trials that measured how long or how hard someone could work, rather than how they looked afterwards.
94
people in trials
14
human studies
10
compounds, animal or cell only
6
trials found nothing
Measured in people
Ranked by how many people, which is a fact about the evidence and not a judgement about the compound. The one at the top is the most studied, which is not the same as the best. Counts are never added across compounds, because the same person can appear in more than one trial.
- 30 people2 human studies1 found nothing
30 adults randomized to endurance exercise, resistance exercise or control: circulating humanin rose significantly after acute endurance exercise but not resistance exercise; MOTS-c showed only a non-significant trend upward, and neither peptide correlated with fitness (VO2max, strength or muscle mtDNA copy number).
Journal of Applied Physiology, 2021 · 30 people
found nothing30 sedentary controls versus 75 professional athletes: professional athletes had lower serum MOTS-c and higher humanin than sedentary controls; MOTS-c did not differ between high- and low/moderate-endurance athletes.
Reviews in Cardiovascular Medicine, 2022 · no headcount in the line
What people using it report
- The effects people describe most are increased energy and mental alertness within the first one to two weeks, sometimes strong enough that users are advised not to dose near bedtime, plus expected improvements in endurance and body composition when paired with training and a calorie deficit. Several sources are explicit that MOTS-c is not described as a fat burner on its own and that people who do not also diet or train report no visible change in body composition.
- 30 people2 human studies
30 adults randomized to endurance exercise, resistance exercise or control: circulating humanin rose significantly after a single bout of endurance exercise but not resistance exercise, and did not correlate with fitness (VO2max, strength or muscle mtDNA copy number).
Journal of Applied Physiology, 2021 · 30 people
30 sedentary controls versus 75 professional athletes: professional athletes had higher serum humanin than sedentary controls, but within the athlete group, high-endurance athletes had lower humanin than low/moderate-endurance athletes of the same age and sex.
Reviews in Cardiovascular Medicine, 2022 · no headcount in the line
- 23 people1 human study1 found nothing
found nothing23 untrained men randomised to 20 mg a day of PQQ or placebo alongside a supervised six-week endurance training programme. There were no significant differences between groups in aerobic performance after endurance training (p > 0.05). Peak oxygen uptake and total test duration improved in both groups, from the training. PGC-1alpha protein rose significantly more in the PQQ group. The authors conclude PQQ does not appear to elicit ergogenic effects on aerobic performance or body composition.
Journal of the American College of Nutrition, 2020 · 23 people
- 11 people1 human study1 found nothing
found nothingThe first randomised controlled trial. 11 healthy men aged 18 to 40, two 2-week cycles of oral clenbuterol at 80 micrograms a day versus placebo with a 3-week washout. Lean mass +0.91 kg (95% CI 0.02 to 1.81, p < 0.05), no effect on fat mass, maximal oxygen uptake -7% (p < 0.001), exercise capacity -4% (p < 0.001), no change in left ventricular mass, blood volume or haemoglobin mass. Muscle protein content rose while 3-hydroxyacyl CoA dehydrogenase activity and OXPHOS complex V fell. The beta-2 signalling response declined across the 2 weeks.
The Journal of Physiology, 2025 · 11 people
- no headcount stated2 human studies1 found nothing
found nothing4 months of urolithin A improved muscle endurance and plasma biomarkers, though 6-minute walk and peak ATP did not differ from placebo.
JAMA Network Open, 2022 · no headcount in the line
About 12% gain in muscle strength and improved VO2 peak and 6-minute walk, though the primary peak-power endpoint was not met.
Cell Reports Medicine, 2022 · no headcount in the line
- no headcount stated1 human study
The same Kiev cohort at 15 years: 39 coronary patients given 6 courses of Epithalamin over 3 years plus basic therapy versus 40 on basic therapy alone, reporting slower cardiovascular aging, preserved physical endurance, normalized melatonin rhythm and significantly lower mortality. The title says pituitary; the text is about the pineal preparation Epithalamin.
Bulletin of Experimental Biology and Medicine, 2011 · no headcount in the line
- no headcount stated1 human study
Small open study: inhaled VIP improved hemodynamics and exercise capacity in primary pulmonary hypertension patients deficient in VIP.
Journal of Clinical Investigation, 2003 · no headcount in the line
- no headcount stated1 human study
Randomised crossover, 9 trained male cyclists, 0.35 g/kg racemic 1,3-butanediol or placebo before and during 85 minutes of steady exercise then a time trial. Blood D-beta-hydroxybutyrate 0.44 to 0.79 mmol/L during exercise (placebo 0.11 to 0.16), peak 1.38 mmol/L after. Moderate to severe gastrointestinal symptoms in 5 of 9; dizziness, nausea or euphoria in 2. Time trial 28.7 versus 28.5 minutes, p = 0.62; power 286 versus 290 W, p = 0.50. No performance benefit. Academic study.
International Journal of Sport Nutrition and Exercise Metabolism, 2019 · no headcount in the line
- no headcount stated1 human study
30 participants, sponsor AgelessRx (a telehealth prescriber), active not recruiting. Arms combine rapamycin 2 to 6 mg weekly, metformin 500 mg daily, low-dose naltrexone, intranasal NAD+, topical glutathione and a proprietary supplement; primary endpoints VO2 max, a cognitive composite and an inflammation index. Cannot isolate either drug. No results posted.
ClinicalTrials.gov, 2025 · no headcount in the line
- no headcount stated1 human study1 found nothing
found nothingRandomised 2:1, 30 overweight or obese adults aged 45 and over, MIB-626 two 500 mg tablets twice daily for 28 days. Body weight fell 1.9 kg (95 percent CI -3.3 to -0.5, P=.008), diastolic blood pressure fell 7.01 mmHg (-13.44 to -0.59, P=.034), total cholesterol fell 26.89 mg/dL (P=.004) and LDL fell 18.73 mg/dL (P=.007). Muscle strength, muscle fatigability, aerobic capacity and stair-climbing power did not change. Insulin sensitivity, hepatic fat and intra-abdominal fat did not change in either group. Metro International Biotech, the manufacturer, is a listed funder. This is a physiologic study with multiple outcomes rather than a trial powered on one of them.
Journal of Clinical Endocrinology and Metabolism, 2023 · no headcount in the line
- no headcount stated1 human study1 found nothing
found nothingIncluded as the contrast, and it is not urolithin B. This is a randomised trial of urolithin A in older adults, in which muscle endurance and plasma biomarkers improved while the six-minute walk and peak ATP did not differ from placebo. Urolithin B has no trial of this kind, or of any kind.
JAMA Network Open, 2022 · no headcount in the line
Measured in animals or cells, not yet in people
These are separated from the trials above rather than ranked against them, because they answer a different question. A result in a rat is a real result and a reason somebody ran the study; it is not a measurement of what happens in you. Where the human work is missing, the reason is usually money rather than failure, and that is set out at the bottom of this page.
- 1 preclinical study
Measured in animals or cells
SLU-PP-332 is a synthetic pan agonist at all three estrogen-related receptors with highest potency at ERR alpha. It increased mitochondrial function and cellular respiration in a skeletal muscle cell line, and in mice increased type IIa oxidative skeletal muscle fibres, enhanced exercise endurance and induced an ERR alpha dependent acute aerobic exercise gene programme. Mice, with no human data.
ACS Chemical Biology, 2023 · animal
What people using it report
- Improved endurance during training after two to three weeks, the main claimed effect.
- 1 preclinical study
Measured in animals or cells
Lys-Glu from month 6 of life increased physical activity and endurance, prolonged lifespan and reduced spontaneous tumors in female CBA mice.
Bulletin of Experimental Biology and Medicine, 2000 · animal
- 1 preclinical study
Measured in animals or cells
SLU-PP-332 triggered an aerobic-exercise-like transcriptional program in muscle and increased running endurance in mice.
ACS Chemical Biology, 2023 · animal
- 1 preclinical study
Measured in animals or cells
AICAR raised endurance in untrained mice by about 44%.
Cell, 2008 · animal
- 1 preclinical study
Measured in animals or cells
GW501516 plus training improved endurance in mice.
Cell, 2008 · animal
- 1 preclinical study
Measured in animals or cells
Each drug alone, started at 4 or 16 months, improved rotarod and endurance and reduced cardiac hypertrophy in aged UM-HET3 mice of both sexes; acarbose changed the cardiac lipidome more than rapamycin; some benefits male-only. Healthspan measures for the single drugs, not the combination.
- 1 preclinical study
Measured in animals or cells
The strongest evidence for the CD38 strategy, and it was not generated with apigenin. 78c, a highly potent and specific thiazoloquinazolinone CD38 inhibitor, reversed age-related NAD decline and improved glucose tolerance, muscle function, exercise capacity and cardiac function in mouse models of natural and accelerated ageing. The effects depended on tissue NAD levels and were reversed by inhibiting NAD synthesis. A declared conflict: an author holds a patent on the use of CD38 inhibitors for metabolic disease. 78c is not commercially available and has no human data.
Cell Metabolism, 2018 · animal
- 1 preclinical study
Measured in animals or cells
Mouse. uPAR-positive senescent cells accumulate with age and were targetable with senolytic CAR T cells. A single administration improved exercise capacity in physiologically ageing mice and ameliorated metabolic dysfunction, including glucose tolerance, in aged and high-fat-diet mice, with long-lasting therapeutic and preventive effect.
Nature Aging, 2024 · animal
- 1 preclinical study
Measured in animals or cells
Balb/c mice, treadmill trained for 4 weeks with AICAR and GW0742. AICAR alone potentiated endurance; the combination increased running time by 138 to 179 percent relative to exercised groups and 355 percent relative to non-exercised groups, with a fuel shift toward fat, glycogen sparing and upregulation of Pgc1a, Pdk4, Cd36 and Lpl in muscle. Mice, in combination with AICAR, not GW0742 alone in a human.
Physiological Reports, 2016 · animal
- 1 preclinical study
Measured in animals or cells
found nothingHuman FNDC5 has an ATA rather than ATG start codon; a human construct with ATA produced about 1 percent of full-length protein. FNDC5 mRNA in human muscle biopsies from two exercise studies was unchanged by endurance or strength training, and recombinant FNDC5 or irisin did not brown human preadipocytes where BMP7 did. Non-US government funded.
PLoS One, 2013 · in vitro
What people using these actually report
Uncontrolled self-reports, gathered from clinic write-ups, regulatory complaint records and public forums, and reproduced here as written. They are the best guide on this page to what people actually do, what they expect, and what goes wrong, and they cannot show that anything works, because nobody was measured against a placebo and the people who saw no effect mostly stopped posting. Both halves of that are true at once. The negative reports are kept in for the same reason.
- The effects people describe most are increased energy and mental alertness within the first one to two weeks, sometimes strong enough that users are advised not to dose near bedtime, plus expected improvements in endurance and body composition when paired with training and a calorie deficit. Several sources are explicit that MOTS-c is not described as a fat burner on its own and that people who do not also diet or train report no visible change in body composition.
Sources: FDA's July 2026 evaluation of MOTS-c-related bulk drug substances, which found no FAERS adverse event reports and no published clinical studies of any kind; a forum thread on iSARMS Forums (retrieved directly) describing dosing and stacking; a 2020 warning thread on eroids.com referenced in search results but not independently retrievable for this entry; and commercial peptide-dosing and side-effect guide sites (Path to Peptides, PerfectB, FormBlends, PeptidesExplorer, Rite Aid, gethealthspan.com), which are vendor- or affiliate-adjacent and are cited here only for the dosing conventions and side-effect categories they describe, not as evidence of anything. Reddit's r/Peptides could not be retrieved for this entry, so nothing above is attributed to any specific post, and no quotation is reproduced from any of these sources.
- Improved endurance during training after two to three weeks, the main claimed effect.
Sources: Forums including r/peptides and r/nootropics, and vendor product pages. Entirely uncontrolled self-report from people taking unverified material, usually while also training.
Why the trial record looks like this
A missing trial is usually a missing sponsor. Nobody runs a nine-figure programme on a molecule they cannot own, so the compounds with the thinnest human records are often the oldest and most freely available ones rather than the weakest. Taking 5-amino-1MQ with SLU-PP-332 as the example, because it states the problem most clearly:
Both of these molecules came out of serious academic pharmacology and both are interesting. The problem is the distance between where the science is and where the product is. A compound with a promising mouse result and no human pharmacokinetics is at the start of a development process that normally takes a decade, and it is being sold in a capsule with a dose printed on the bottle.
The 200 to 1 ratio is the second thing. Someone buying this for the exercise mimetic is getting a quarter of a milligram of it alongside fifty milligrams of something else. If the ERR agonist is what interests you, this vial gives you a trace of it.
The oral presentation is the third. Capsules and tablets with printed milligram doses are the format of medicines and supplements, not of research chemicals, and the format carries an implication of human testing that has not happened for either ingredient.
A compound appears here only when a citation on its own page states this outcome and reports a result for it; naming it is not enough. Human, animal and cell work are counted separately and never merged. Participant counts are read from the study lines and deliberately undercount. Nothing here is advice, and nothing here is a recommendation to take or to avoid anything.