In mice, a single dose of SLU-PP-332 switched on in muscle the same programme as aerobic exercise, raising mitochondrial respiration, fatty acid oxidation and energy expenditure, and dosing in obese mice reduced fat mass gain and improved insulin sensitivity. These results have not yet been repeated in humans.
SLU-PP-332 is sold as a molecule meant to imitate the effects of endurance training. The marketing name is "exercise in a pill", and that is a shorthand worth taking apart. Below you will find what the research showed and what was missing from it, because with this substance the second list matters as much as the first.
What is SLU-PP-332?
It is a synthetic small molecule, not a peptide, even though it is sold in the same place as peptides. It acts as a pan-agonist of the estrogen-related receptors, designated ERR alpha, ERR beta and ERR gamma, most strongly at ERR alpha. The molecule was developed in the laboratory of Thomas Burris.
ERR receptors are nuclear receptors, that is, proteins that switch whole groups of genes on and off. Endurance exercise is one of the things that activates them, and that is where the term exercise mimetic comes from.
What was shown in mice?
A single dose triggered in mice a transcriptional programme matching acute aerobic exercise. It increased mitochondrial respiration and fatty acid oxidation in skeletal muscle and raised energy expenditure. That is the heart of the mechanism: the molecule switches on in muscle a programme that running normally switches on.
In diet-induced obese mice and in ob/ob mice, dosing reduced fat mass gain and improved insulin sensitivity. An increase in oxidative type IIa muscle fibres and improved endurance capacity were also described.
What was missing from that research?
People. All the efficacy data come from studies in mice, none of the results has been repeated in humans, and no clinical trials have been run. That is not a footnote; it is the main reservation about this molecule.
Three practical things follow from the absence of human research. There is no established dose, there is no described safety profile in humans, and it is not known whether the effects seen in rodents carry over to human metabolism at all. The history of metabolic pharmacology holds plenty of molecules that worked beautifully in mice and did not repeat the result in people.
Does it replace training?
No, and that is not how the molecule works. In mice it triggered part of the muscle's response to exercise, not the whole physiology of training. Training also changes the circulatory system, hormonal balance, bone density and neuromuscular skill, and none of those effects can be produced by an agonist of a single receptor family.
What is its legal status?
SLU-PP-332 is not an approved medicine in any country and has no status as a supplement. It is sold as material for research purposes and that is how we describe it in the shop. More on what that status means for a buyer is in the article on the legal status of peptides.
| Question | State of knowledge today |
|---|---|
| Mechanism | Pan-agonist of ERR alpha, beta and gamma, strongest at ERR alpha |
| Animal research | Mice: higher energy expenditure, fat oxidation, endurance |
| Research in humans | None |
| Established dose | None |
| Status | Research material, not approved as a medicine |
Where SLU-PP-332 sits among other metabolic molecules
If you are looking at body weight, it helps to know how this molecule compares with the incretin analogues. Semaglutide, tirzepatide and retatrutide have clinical trials in humans behind them, phase 3 included, and that is a difference of kind rather than degree. The mechanism of that group is taken apart in the article on GLP-1 and the incretins, and the comparison between them in the article on the three weight-loss peptides.
The other neighbouring molecule is MOTS-c, also studied for metabolism and also without clinical trials; it is covered in a separate article on MOTS-c and mitochondrial peptides. Both sit in the weight-loss peptides category, alongside SLU-PP-332.
Frequently asked questions
Is SLU-PP-332 a peptide?
No. It is a synthetic small molecule acting on ERR receptors. It is sold alongside peptides but belongs to a different group of compounds.
Have there been studies in humans?
No. All efficacy data come from studies in mice and have not been repeated in people.
What does the term exercise mimetic mean here?
The molecule stimulates ERR receptors, which endurance exercise also activates. In mice a single dose switched on a transcriptional programme matching acute aerobic exercise.
Will SLU-PP-332 replace training?
No. In mice it triggered part of the muscle's response to exercise, not the whole physiology of training, including the changes in the circulatory system and in bone.
What is the established dose?
There is none. Without clinical trials in humans there is no basis for publishing a protocol, so we do not publish one.
Where this information comes from
The mechanism as a pan-agonist of ERR alpha, beta and gamma, the origin of the molecule in the Burris laboratory, the transcriptional programme after a single dose, the rise in mitochondrial respiration and fatty acid oxidation, and the results in diet-induced obese and ob/ob mice come from the published work on SLU-PP-332. The absence of clinical trials was confirmed by a search of trial registries. These sources were checked on 6 September 2026.
This is information about a product and about the state of the research, not medical advice. SLU-PP-332 is sold as research material, and judging whether any use is warranted is a doctor's job.
Sources
- Billon C, Sitaula S, Banerjee S et al. Synthetic ERRα/β/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity. ACS Chemical Biology, 2023, 18(4): 756-771. https://doi.org/10.1021/acschembio.2c00720
- Billon C, Schoepke E, Avdagic A et al. A Synthetic ERR Agonist Alleviates Metabolic Syndrome. Journal of Pharmacology and Experimental Therapeutics, 2024, 388(2): 232-240. https://doi.org/10.1124/jpet.123.001733