SLU-PP-332: research, side effects and dosage in studies

In short

SLU-PP-332 is a small molecule designed in the laboratory that activates the estrogen-related ERR receptors, and it is called an "exercise mimetic" [1]C. It has only been studied in mice and cells, and it has no marketing authorisation in the EU [14]regulator.

• In mice, one week of treatment lengthened running time by about 70% and running distance by about 45% [1]C. It has not been studied in humans, and no human study has been registered (as of October 2026).
• All animal studies come from one research network or its collaborations, and its key researchers hold shares in companies developing ERR drugs [1, 6]C [10]D.
• SLU-PP-332 is not absorbed by mouth; in the mouse studies it was injected into the abdominal cavity. The sister molecule SLU-PP-915 was developed to be absorbed by mouth [6]C.
• Side effects in humans are unknown, because there are no human studies. In mice no overt toxicity was seen in a 10-day or a six-week experiment [1, 3]C.
• The WADA 2027 list names SLU-PP-332 from 1 January 2027 [18]regulator; the 2026 list does not name it, but class S0 prohibits non-approved substances [13]regulator. Doping laboratories have already published the breakdown products needed to detect it [8, 9]D.

What is SLU-PP-332?

SLU-PP-332 is a synthetic small molecule that activates all three estrogen-related receptors (ERR-alpha, ERR-beta and ERR-gamma), most strongly ERR-alpha [1]C. It is neither a peptide nor a hormone.

The series was developed at Saint Louis University and its partner groups [1]C [7]D. The sister molecule SLU-PP-915 has a different structure but activates the same receptors [3]C [7]D.

"Exercise mimetic" means a substance that imitates the effects of exercise in the body. SLU-PP-332 got the label because it switched on the same gene programme in mouse muscle as a single bout of endurance exercise [1]C.

There is little literature, and it dates from 2023-2026. No publication is a human study (as of October 2026). All substances on the site: Peptides A-Z.

Evidence at a glance

Each cell gives the kind of study and its source. The letter is the evidence level, not the result.

"-" = no such study is known.

What is SLU-PP-332 studied for?

SLU-PP-332 is studied in mouse models of metabolic, heart, kidney and muscle disease. No use is approved [14]regulator.

• Endurance and muscle: an effect imitating endurance exercise in mice [1]C.
• Obesity and metabolic syndrome: in obese mice [2]C.
• Heart failure: in mice whose hearts were put under pressure overload [3]C.
• Kidney ageing: in 21-month-old mice [4]C.
• Ageing muscle: in human muscle cells in culture, not in humans [5]D.
• Doping control: doping laboratories study how its use can be detected [8, 9]D.

According to a systematic review in Spanish, the evidence comes entirely from animal and cell studies, and confirming efficacy and safety would require clinical trials [11].

How does SLU-PP-332 work?

ERR receptors are nuclear receptors that control genes for building mitochondria, cellular energy production and fat burning. They are needed for muscle to adapt to endurance exercise [6]C.

ERR receptors are called orphan receptors [6]C: for ERR-alpha, for example, no activating molecule made by the body is known [12]. SLU-PP-332 is one of the few synthetic substances that can activate them in a living animal [1]C.

In mice SLU-PP-332 increased oxidative type IIa muscle fibres and switched on the same gene programme as running, for example the Ddit4 gene [1]C [6]C. When ERR-alpha had been removed from the mice's muscle, the substance no longer improved endurance [1]C. In the heart the effect ran mainly through ERR-gamma [3]C.

Has SLU-PP-332 been studied in humans?

No. SLU-PP-332 has not been given to humans in any published study, and no human study of SLU-PP-332 or SLU-PP-915 has been registered (as of October 2026).

The closest to humans are two kinds of laboratory work. In an Italian pilot study, 20 women having hip surgery were divided into active and inactive, and cells grown from the inactive women's muscle samples were treated with SLU-PP-332 in culture [5]D. Doping laboratories, in turn, studied how human liver enzymes break the substance down in a test tube [8, 9]D.

Neither tells what the substance does to a person. Test-tube results and animal studies are preclinical evidence.

Promising, but only in animals and cells

All the promising findings for SLU-PP-332 come from animal or cell studies. They have not been studied in humans.

• Endurance without training no human studies

  After one week of treatment, sedentary mice ran about 70% longer and about 45% further than control mice. There were more oxidative muscle fibres, and after two weeks of treatment grip strength was also greater [1]C. The sister molecule SLU-PP-915 improved running distance and time as much [6]C.

  If it held in humans: the substance could increase endurance without training.

  Why it might not translate: the groups had six mice, and the substance was injected into the abdominal cavity because it is not absorbed by mouth [1, 6]C. A mouse treadmill test does not tell how human performance would change. The results come from the same research network, whose key researchers hold shares in companies developing ERR drugs [1, 6]C.

  Evidence now: two mouse studies from the same group [1, 6]C; no registered human study.

• Obesity and insulin sensitivity no human studies

  In diet-induced obese and genetically obese mice, SLU-PP-332 increased energy expenditure and fat burning, reduced fat build-up and improved insulin sensitivity [2]C.

  If it held in humans: the substance could help in obesity and in the early stages of type 2 diabetes.

  Why it might not translate: mouse models of obesity do not reliably predict weight change in humans, and the result comes from one group [2]C.

  Evidence now: one mouse study; no human study.

• Heart failure no human studies

  In mice whose hearts were strained by six weeks of pressure overload, both SLU-PP-332 and SLU-PP-915 improved the heart's pumping, reduced scarring and increased survival [3]C.

  If it held in humans: an ERR agonist could be a new way to treat heart failure.

  Why it might not translate: the mouse pressure-overload model differs from human heart failure, and no repeat of the single study's result has been published [3]C.

  Evidence now: one mouse study; no human study.

• Kidney ageing no human studies

  In 21-month-old mice, eight weeks of treatment reversed the age-related leak of protein into the urine, loss of the kidney's filtering cells, mitochondrial dysfunction and inflammation [4]C.

  If it held in humans: the substance could slow kidney ageing.

  Why it might not translate: the result comes from one mouse study, and a mouse ages over months, a human over decades [4]C.

  Evidence now: one mouse study; no human study.

• Ageing and inactive muscle no human studies

  In cells grown from the muscle of inactive women, SLU-PP-332 reduced oxidative stress, cell ageing and cell toxicity and increased the fusion of muscle cells into muscle fibres [5]D.

  If it held in humans: the substance could counter muscle loss caused by inactivity.

  Why it might not translate: a concentration acting on cells in a test tube does not tell what would happen in the body, and the women studied were not given the substance [5]D.

  Evidence now: one pilot study in cells; no human study.

Who studies SLU-PP-332?

All animal studies of SLU-PP-332 come from a network built around Saint Louis University and the University of Florida or from its collaborations, and the network's key researcher is Thomas Burris [1, 2, 3, 4, 6]C. The first paper also involved a Salk Institute group [1]C, which had run the well-known exercise mimetic experiment in 2008 [17]C.

The ties are declared in the publications: some authors hold shares in Myonid Therapeutics, and Burris also in Pelagos Pharmaceuticals. Both develop drugs acting on ERR receptors, and SLU-PP-915 is covered by Saint Louis University's intellectual property [1, 6]C [10]D.

Independent work includes an Italian cell study [5]D and analyses by the doping laboratories in Cologne and Los Angeles [8, 9]D. The kidney study was done at Georgetown University in collaboration with the network [4]C.

Who wrote this page: the editorial team

This page was written by the Molecular Recovery editorial team. The draft was made with the help of AI, and the claims were checked against the sources (AI policy). The page has not been medically reviewed. How we work: About us.

How long does SLU-PP-332 stay in the body?

Not known. No half-life of SLU-PP-332 in humans or animals has been published.

• In mice: two hours after an injection into the abdominal cavity, levels were about 0.6 micromolar in muscle and about 0.2 micromolar in the blood. According to the researchers this is enough to use the substance in laboratory animals [1]C.
• By mouth: SLU-PP-332 is not absorbed. That is why SLU-PP-915, which is absorbed, was developed [6]C.
• Breakdown: with human liver enzymes in a test tube, SLU-PP-332 gave 9 breakdown products in one study and 22 in another [8, 9]D.

What are the side effects of SLU-PP-332?

Side effects in humans are not known, because the substance has not been given to humans. The safety data from animal studies are short and limited.

What users report. In the Reddit accounts we compiled (not research), 40 of 72 people (56%) reported some harm, most often: fatigue (13, 18%), feeling hot or sweating (11, 15%) and palpitations, heart rate or blood pressure (10, 14%). People tend to post when something goes wrong, so this share does not tell how common harms are. SLU-PP-332 has not been given to humans in studies, so the accounts are about products bought online whose contents are unknown. Of those who stated the route, 29 took it by mouth and 4 injected it, although researchers say the substance is not absorbed by mouth. 27 of 72 people (38%) used other substances at the same time, most often retatrutide (16), 5-Amino-1MQ (5), BPC-157 (5), MOTS-c (5), TB-500 (5) and one more equally common. The harms in detail: SLU-PP-332 user experiences.

Seen in animals

In mice ten days of treatment caused no overt toxicity: blood counts and electrolytes were normal, and creatine kinase, a marker of muscle damage, did not rise [1]C. In the heart study no overt toxicity was seen over six weeks [3]C. According to a review, animal studies have shown no evident toxicity [11].

What has not been studied

Long-term safety, cancer risk and effects on the unborn child or fertility have not been published. This is an important gap, because according to a review ERR-alpha is linked to the onset and progression of several cancers, and a high level of it is a sign of poor prognosis in many cancers [12]. Whether activating it affects cancer risk is not known. Side effects more generally: side effects in studies.

Interactions and who has no data

There is no research data on interactions, because the substance has not been given to humans. Liver enzymes modify the substance in many ways in a test tube [8, 9]D, but whether it affects the breakdown of other medicines has not been studied. There is no data on pregnancy, breastfeeding or children.

What speaks against it and what is not known

No direct counter-evidence was found, but the evidence is weak in structure: one research network, small groups of mice and no human data.

Counter-evidence

• No null results or failed replications have been published. This may also mean that no independent replications have been done.
• Ties. Key researchers hold shares in companies developing ERR drugs [1, 6]C [10]D.
• Absorption. The substance is not absorbed by mouth [6]C, so there is no basis for an effect of an SLU-PP-332 product sold for taking by mouth.
• The cancer question. ERR-alpha is linked to the progression of many cancers [12], and the long-term effects of activating it have not been studied.

What the evidence does not support

• "SLU-PP-332 is exercise in a pill": it has not been studied in humans, and it is not absorbed by mouth [6]C.
• "SLU-PP-332 causes weight loss": fat loss has only been shown in obese mice [2]C.
• "SLU-PP-332 is safe": safety has not been studied in humans, and in mice safety has been reported for at most six weeks [1, 3]C.
• "SLU-PP-332 is allowed in sport because it is not on the list": class S0 prohibits non-approved substances that the list does not otherwise cover [13]regulator, and the 2027 list names it [18]regulator.

What is not known

• Whether the substance works in humans at all.
• What its half-life and a safe exposure are.
• Whether the mouse results hold up in an independent laboratory.

SLU-PP-332 dosage in studies

SLU-PP-332 has no approved dosage and no published human dose. The figures below are animal doses in mice, not recommendations.

What the figures do not tell you. A mouse dose cannot be converted to a human dose by body weight, and injection into the abdominal cavity is not used in humans. Because there are no human studies, no safe or effective human dose is known, and so the substance has no dose page or calculator of its own. On reading study doses in general: dosage in studies.

SLU-PP-332 vs SLU-PP-915: what is the difference?

Both are ERR agonists from the same group, but they differ in structure, and only SLU-PP-915 is absorbed by mouth [3, 6]C.

• Endurance: injected into the abdominal cavity, both improved running distance and time in mice to the same extent [6]C.
• By mouth: SLU-PP-915 kept its effect when given by mouth, once exposure was taken into account. SLU-PP-332 is not absorbed [6]C.
• Heart: both improved heart failure in mice in the same study [3]C.
• Structure: SLU-PP-915 has a boronic acid group, which improved its resistance to breakdown by liver enzymes in a test tube [7]D.

The older exercise mimetic AICAR lengthened running distance in mice by 44% in 2008 [17]C. AICAR acts through a different route, the enzyme AMPK [17]C. None of these has been studied in humans as an endurance enhancer.

Another substance called an exercise mimic is AICAR. A comparison of the three: Exercise mimetics: AICAR, SLU-PP-332 and MOTS-c.

SLU-PP-332 combinations

Combinations of SLU-PP-332 with other substances have not been studied. The only combination studied is with exercise: in mice SLU-PP-915 strengthened the effect of training on mitochondrial genes in muscle [6]C.

Combinations have not been studied in humans. On blends in general: blends.

Is SLU-PP-332 legal in Finland?

SLU-PP-332 has no marketing authorisation in the EU, so it cannot be marketed as a medicine [14]regulator. It is not listed on Fimea's medicines list [15]regulator.

• Marketing authorisation. The EMA data set of centrally authorised medicines (14 Oct 2026) contains neither SLU-PP-332 nor SLU-PP-915 [14]regulator.
• Medicines list. The fact that a substance is not on the medicines list does not settle a product's status. Under the Medicines Act, Fimea decides when needed whether a substance or product is a medicine [16]regulator.
• The label "for research use only" means the product is not intended for humans. For SLU-PP-332 it describes the situation exactly: the substance has only been used in laboratory animals and cells [1]C.

Overview of the law: Peptides and the law in Finland. Bringing substances back from travel: Travelling with peptides.

This is not legal advice. Disclaimer.

Is SLU-PP-332 doping?

Yes, from 1 January 2027 at the latest: the WADA 2027 Prohibited List names SLU-PP-332 and SLU-PP-915 in class S4.4.1 [18]regulator. The 2026 list does not name it, but it is probably prohibited already: class S0 of the WADA 2026 Prohibited List prohibits at all times substances that the list does not otherwise cover and that have no regulatory approval for human use, for example substances in clinical or preclinical development [13]regulator. SLU-PP-332 has no marketing authorisation [14]regulator.

According to WADA, a substance is placed in S0 after a case-by-case evaluation, and the fact that a substance is not mentioned on the list does not mean that it is permitted [13]regulator. Competitive athletes should check with their own anti-doping organisation.

Doping laboratories are already preparing for testing. The Cologne laboratory identified 9 breakdown products for SLU-PP-332 and 7 for SLU-PP-915 [8]D, and the Los Angeles Olympic laboratory 22 breakdown products, naming the most useful ones for testing [9]D.

How to judge the quality of an SLU-PP-332 product

There is no certainty about what an SLU-PP-332 product contains without analysis. No analysis of products on sale has been published, so nothing is known about their quality.

On a certificate of analysis (COA) look at the method: liquid chromatography, HPLC, gives purity and mass spectrometry (MS) identifies the molecule. Doping laboratories have published the mass spectrometric signatures of SLU-PP-332 and SLU-PP-915 [8]D. A guide: How to read a COA.

The names are easily confused: SLU-PP-332 and SLU-PP-915 are different molecules [3]C, and only the latter is absorbed by mouth [6]C.

The future: what comes next?

No human studies have been registered (as of October 2026). Development is still at the stage of chemistry and animal studies.

In 2026 the same research network published a systematic modification of the SLU-PP-332 structure: some new derivatives worked as well and dissolved better or resisted breakdown better [10]D. The researchers see SLU-PP-915, which is absorbed by mouth, as a tool for studying long-term effects [6]C. According to a review, the next necessary step would be clinical trials [11].

FAQ

Read the research yourself: sources

Every source opens the original publication or the regulator's page. The level shows what the source itself reports.

1. 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 Chem Biol. 2023;18(4):756-771. PMID 36988910 C
2. Billon C, Schoepke E, Avdagic A, et al. A synthetic ERR agonist alleviates metabolic syndrome. J Pharmacol Exp Ther. 2024;388(2):232-240. PMID 37739806 C
3. Xu W, Billon C, Li H, et al. Novel pan-ERR agonists ameliorate heart failure through enhancing cardiac fatty acid metabolism and mitochondrial function. Circulation. 2024;149(3):227-250. PMID 37961903 C
4. Wang XX, Myakala K, Libby AE, et al. Estrogen-related receptor agonism reverses mitochondrial dysfunction and inflammation in the aging kidney. Am J Pathol. 2023;193(12):1969-1987. PMID 37717940 C
5. Bonanni R, Falvino A, Matticari A, et al. Targeting ERRs to counteract age-related muscle atrophy associated with physical inactivity: a pilot study. Front Physiol. 2025;16:1616693. PMID 40692696 D
6. Billon C, Appourchaux K, Côté I, Burris TP. An orally active estrogen receptor-related receptor agonist, SLU-PP-915, enhances aerobic exercise capacity. J Pharmacol Exp Ther. 2026;393(1):103787. PMID 41421047 C
7. Hampton CS, Sitaula S, Billon C, et al. Development and pharmacological evaluation of a new chemical series of potent pan-ERR agonists, identification of SLU-PP-915. Eur J Med Chem. 2023;258:115582. PMID 37421886 D
8. Möller T, Krug O, Thevis M. In vitro metabolism and analytical characterization of SLU-PP-332 and SLU-PP-915: novel pan-ERR agonists with doping potential. Rapid Commun Mass Spectrom. 2026;40(8):e70039. PMID 41588687 D
9. Avliyakulov NK, Sobolevsky T, Ahrens E. Analysis and identification of in vitro metabolites of exercise mimetic SLU-PP-332 ERRα/β/γ agonist for doping-control purposes. Drug Test Anal. 2026;18(3):439-450. PMID 41688415 D
10. Okda HE, Zhao P, Hayes M, et al. Chemical optimization of the exercise mimetic SLU-PP-332 enables insight into estrogen-related receptor signaling. Int J Biol Macromol. 2026;355:151450. PMID 41850449 D
11. de Souza-Lima J, Astrosa-Martin BD, Galaz-Rodríguez CA, et al. [Pharmacological activation of ERRα/β/γ as an exercise mimetic: potential therapeutic applications]. Rev Med Chil. 2026;154(2):237-245. Article in Spanish, systematic review of animal and cell studies. PMID 42024694 (review)
12. Ranhotra HS. Estrogen-related receptor alpha in select host functions and cancer: new frontiers. Mol Cell Biochem. 2022;477(5):1349-1359. PMID 35138514 (review)
13. World Anti-Doping Agency. 2026 Prohibited List, class S0 Non-approved substances (SLU-PP-332 is not named in the list); and the Prohibited List page, Q&A "Are all drugs not mentioned on the Prohibited List permitted?" (read 15 Oct 2026). WADA regulator
14. European Medicines Agency. Medicine data (centrally authorised medicines, data set generated 14 Oct 2026): no product with SLU-PP-332 or SLU-PP-915. EMA regulator
15. Finland. Lääkeluettelo (Fimea medicines list), 230/2025, annexes 1 and 1 A: SLU-PP-332 is not listed (searched 15 Oct 2026). Finlex regulator
16. Finland. Medicines Act (Lääkelaki) 395/1987, section 6: Fimea decides, when needed, whether a substance or product is to be regarded as a medicine. Finlex regulator
17. WADA. Prohibited List 2027 (tracked-changes version, 26 Aug 2026; approved 10 Sep 2026, in force 1 Jan 2027), class S4.4.1. wada-ama.org (PDF) regulator
18. Narkar VA, Downes M, Yu RT, et al. AMPK and PPARdelta agonists are exercise mimetics. Cell. 2008;134(3):405-415. PMID 18674809 C

Sources searched and read on 15 Oct 2026: PubMed abstracts, ClinicalTrials.gov, the EMA medicine data and Fimea's medicines list. The mouse doses and group sizes of sources 1 and 3 are from the full texts. The WADA 2026 list was read on 15 Sep 2026 and the list page on 15 Oct 2026; the 2027 list from a PDF saved on 12 Oct 2026.

Evidence levels: A = randomised human trial or meta-analysis · B = observational human study or case series · C = animal study · D = cell or laboratory study · E = not peer-reviewed · regulator = a regulator's assessment or decision, not research evidence. The marker official means official product information (summary of product characteristics or label); it is not research evidence. For a review, the level shows what kind of research the statement rests on. No level: statements that something has not been studied, reviews' interpretations, named hypotheses and the general rules in our certificate-of-analysis guide.

Content is general information about research, not medical advice. If you have symptoms, contact a healthcare professional.