SLU-PP-332 vs MOTS-C
SLU-PP-332 is a synthetic small molecule, not a peptide: it is a pan-agonist of the estrogen-related receptors ERRalpha, ERRbeta and ERRgamma, the orphan nuclear receptors that work with PGC-1 coactivators to drive mitochondrial biogenesis and oxidative metabolism. MOTS-c is a 16-amino-acid microprotein encoded within the mitochondrial 12S rRNA gene and described as a retrograde signal acting through AMPK. Both have been labelled exercise mimetics in the literature, which is why they are so often set against each other. No published experiment has tested them side by side, in any model. Two review articles engage both compounds without administering either: a 2025 systematic review of exercise mimetics in ageing and a 2026 review of cardiac mitochondrial biogenesis. Everything else is separate: different molecular classes, different assay systems, and two literatures that have never met in a single design.
No study has compared them directly.
Everything below is drawn from separate studies that used different models, endpoints and species. That is a real limit on what can be concluded, not a formality.
No study has administered SLU-PP-332 and MOTS-c in the same experiment, in vitro or in vivo. Searches of PubMed and Europe PMC, including a cross-check of every indexed publication naming SLU-PP-332 against the MOTS-c literature, returned only two records that engage both, and both are reviews. A 2025 systematic review of exercise mimetics in ageing, which selected and discussed 97 research articles retrieved for that term, cited the reported exercise-mimetic properties of SLU-PP-332 and separately described MOTS-c as a mitochondrially encoded hormone whose plasma levels correlate with insulin resistance. A 2026 review of mitochondrial biogenesis and energy metabolism in the heart listed small-molecule ERR agonists including SLU-PP-332 as promising in animal studies but unevaluated in patients, and described MOTS-c and its analogues as a candidate therapeutic class acting through AMPK. Neither review compared the two, and neither generated new data on either compound.
The 2 publications that cover both
- 01Systematic review2025
Exercise Mimetics in Aging: Suggestions from a Systematic Review
Giacomello E, Nicoletti C, Canato M, Toniolo L · Nutrients · systematic search of PubMed and Scopus for the term exercise mimetics, from which 97 research articles were selected and discussed
The review surveyed compounds and physical strategies proposed as exercise mimetics and covered both compounds within that survey, without administering either and without comparing them. It cited the reported exercise-mimetic properties of the synthetic ERR agonist SLU-PP-332, and separately described MOTS-c as a 16-amino-acid hormone encoded by mitochondrial rRNA whose plasma levels had been shown to correlate with insulin resistance. Its overall conclusion was that a substantial share of the exercise mimetics identified were products of natural origin or dietary supplements.
- 02Review2026
Regulation of mitochondrial biogenesis and energy metabolism in the heart
She P, Mo F, Zhu P, Zhong TP · Chin Med J (Engl) · narrative review of the transcriptional and signalling control of mitochondrial biogenesis and energy metabolism in the heart, covering candidate pharmacological interventions
The review placed both compounds among candidate approaches to cardiac mitochondrial biogenesis and administered neither. It reported that small-molecule agonists targeting ERR activity, naming SLU-PP-332 and the related analogue SLU-PP-915, showed promise in animal studies while their efficacy and safety in patients remained to be evaluated in clinical trials. It separately described MOTS-c and its analogues as a new class of potential therapeutics acting through AMPK, with reported effects on insulin resistance, inflammation and age-related metabolic and cardiovascular disorders.
Side by side.
| SLU-PP-332 | MOTS-C | |
|---|---|---|
| Evidence maturity | Preclinical only | Preclinical only |
| Studies cited here | 13 | 15 |
| Published 2023 or later | 13 | 12 |
| Newest paper | 2026 | 2026 |
| Sequence and origin | Not a peptide. A synthetic small molecule developed as a pan-agonist of the estrogen-related receptors ERRalpha, ERRbeta and ERRgamma, first reported in 2023 and with no endogenous counterpart. | A 16-amino-acid microprotein encoded within the mitochondrial 12S rRNA gene, so the molecule is genuinely endogenous. It was reported in 2015 as a mitochondrial-derived peptide targeting the folate-methionine one-carbon cycle. |
| Mechanism as described in the literature | Nuclear receptor agonism. Reported work describes activation of ERRalpha, ERRbeta and ERRgamma with PGC-1 coactivation, driving mitochondrial biogenesis, fatty acid oxidation and an acute aerobic exercise transcriptional signature in rodent skeletal muscle, with a further link to autophagy through TFEB. | Retrograde mitochondrial-to-nuclear signalling. Reported effects include AMPK activation, modulation of folate-methionine one-carbon metabolism and nuclear stress-response gene expression, with a 2024 report describing direct binding and activation of casein kinase 2 in skeletal muscle. |
| Size of the evidence base | Small and entirely preclinical. Rodent in vivo studies in obesity, heart failure and kidney ageing, cell-based transactivation and autophagy work, medicinal-chemistry optimisation around the scaffold, and analytical metabolite characterisation for doping control. | Larger and mixed. Interventional data come from rodent and cell-culture studies spanning a decade, and there is a substantial separate human literature that measures circulating concentrations as a candidate biomarker rather than administering the peptide. |
| Best-characterised finding | An acute aerobic exercise-like transcriptional signature in mouse skeletal muscle, with increased type IIa oxidative fibres and improved treadmill endurance, an effect reported to depend on ERRalpha. | Prevention of insulin resistance in mice. The 2015 report found that administration prevented age-dependent and high-fat-diet-induced insulin resistance and diet-induced obesity, and a 2021 study reported improved physical performance across young, middle-aged and old animals. |
| Human data | None. No human clinical trial has been published or registered. The only work using human material is a pilot study in which primary myoblasts isolated from physically inactive women were treated in culture; no participant received the compound. | No administration study exists. Human research measured endogenous concentrations in obesity, polycystic ovary syndrome, acute coronary syndrome, heart failure and after exercise or heat exposure, and those concentrations moved in opposite directions across conditions. |
| Recency of primary research | Active and accelerating. Primary reports appeared from 2023 onward, with 2026 publications covering analogue optimisation, the orally active analogue SLU-PP-915 and two independent in vitro metabolite studies conducted for anti-doping purposes. | Active and long-running. Primary work has been published continuously since 2015, including 2026 rodent bioenergetics studies and several 2026 human biomarker cohorts in obesity, polycystic ovary syndrome and cerebral palsy. |
| Safety signals reported | A 2026 systematic review of the preclinical literature reported no evident toxicity in the rodent models surveyed. Long-term toxicity, carcinogenicity and reproductive effects have not been characterised, and there is no human safety dataset. | No human safety dataset exists, because no dosing study has been published. Preclinical reports have not described major toxicity, but that observation is confined to rodent and cell-culture models. |
| Regulatory and anti-doping status | Not approved anywhere and not in clinical development. Two 2026 analytical papers characterised its in vitro metabolites specifically to support doping-control screening, one of them describing the compound as having doping potential. | Not approved anywhere. No trial administering the peptide to humans has been published or registered, so pharmacokinetics and dosing in people are unestablished. |
And what it does not.
Both compounds are described as exercise mimetics, and that shared label is close to the only thing the literature actually puts them in common. No experiment has run them together, and the two reviews that name both do so in separate paragraphs. SLU-PP-332 is a small-molecule nuclear receptor agonist whose evidence is rodent and cell-culture work, reasonably coherent within its own terms, with no human trial published or registered and its metabolites already being characterised for doping detection. MOTS-c is an endogenous mitochondrial microprotein with a decade of rodent and cell work plus a large human biomarker literature that describes associations rather than effects, and no human dosing study either. Neither compound therefore has evidence that a person given it would gain endurance, lose fat or improve insulin sensitivity, because neither has been given to a person in a published trial. The two act on different molecular machinery, and the claim that they are complementary or additive has not been tested in any model.
Common questions.
- Has any experiment tested SLU-PP-332 and MOTS-c side by side?
No. A cross-check of every publication indexed for SLU-PP-332 against the MOTS-c literature returned only two records that engage both, and both are reviews that administered nothing. One is a 2025 systematic review of exercise mimetics in ageing, the other a 2026 review of cardiac mitochondrial biogenesis. Neither compared the compounds, ranked them or reported new data on either. Any claim that one outperforms the other rests on comparing separate experiments that used different models, endpoints and readouts.
- Is SLU-PP-332 a peptide?
It is not, despite being sold alongside peptides. SLU-PP-332 is a synthetic small molecule that acts as an agonist at the estrogen-related receptors ERRalpha, ERRbeta and ERRgamma, which are nuclear receptors rather than cell-surface targets. MOTS-c, by contrast, is a 16-amino-acid microprotein encoded in mitochondrial DNA. The difference matters for how each is studied: the SLU-PP-332 literature includes medicinal-chemistry optimisation and liver-fraction metabolite profiling, work that has no counterpart in the MOTS-c record.
- Why do both compounds get called exercise mimetics?
Because each has been reported to reproduce part of the transcriptional or metabolic response to exercise in preclinical models. SLU-PP-332 induced an acute aerobic exercise-like gene signature in mouse skeletal muscle and improved treadmill endurance in an ERRalpha-dependent manner. MOTS-c expression rises in human skeletal muscle and plasma after acute exercise, and administration improved physical performance in mice. The 2025 systematic review that names both grouped them under that heading without testing whether either reproduces exercise in people.
- Does the human myoblast study mean SLU-PP-332 has been tested in humans?
No. That pilot study isolated primary myoblasts from physically inactive women and treated the cells in culture, reporting reduced NOX4, increased SIRT1, PGC-1 alpha, ERRalpha and FNDC5, lower oxidative stress and senescence markers, and increased myotube formation. No participant was given the compound. It is a cell-culture experiment using human-derived material, which says nothing about absorption, distribution, dosing, tolerability or any clinical outcome in a living person.
- What does the anti-doping literature add to the picture?
It shows that detection work is running ahead of efficacy work. Two independent 2026 studies incubated SLU-PP-332 with human liver preparations and characterised its metabolites specifically to support doping-control screening, one describing the compound as having doping potential. Comparable analytical attention has been directed at the related analogue SLU-PP-915. That effort establishes that the compound is expected in the sporting supply chain; it does not establish that it works, is safe, or has any characterised human pharmacology.
For research purposes only. Not for human consumption, diagnosis, treatment, or prevention of any condition. Nothing on this page is medical advice, and no comparison here should be read as a recommendation of either compound.