"Exercise in a pill" is a headline most compounds never earn, and SLU-PP-332 earned it from real papers in real journals. What the headline hides is how small that evidence is, and what sort of evidence it is. Every result behind it comes from mice or from cells in a dish. Nobody has published a study of a person taking it, and the molecule is not a peptide at all. This page counts what exists and reports what each study actually measured; it gives no usage guidance, per our editorial standards.
What it is
SLU-PP-332 is a synthetic small molecule from the Saint Louis University laboratory of Thomas Burris. It activates the three estrogen-related receptors, ERRα, ERRβ and ERRγ. These are "orphan" nuclear receptors that switch on genes for mitochondrial energy production, and despite the name they are not activated by estrogen. The founding paper reported that it acts on all three receptors, with the highest potency at ERRα, and that it was the first compound with enough exposure in the body to test ERR activation in living animals (Billon 2023, PMID 36988910).
It has no amino-acid chain. Shops list it next to peptides and social posts call it one, but the papers describe it as a small organic compound built by structure-based design. The plain "what is it" entry is Peptide Lexicon's SLU-PP-332 page; this page is about the performance claim.
Where "70% longer" comes from
The number that circulates is real, and it comes from one figure in the 2023 paper. Read in full (PMC11584170), the endurance experiment was:
| Detail | What the paper reports |
|---|---|
| Animals | Male C57BL/6J mice, 12 weeks old, six per group |
| Amount and route | 50 mg/kg twice a day, injected into the abdomen (intraperitoneal) |
| Length | About a week (the results text says 7 days, the methods 6) |
| Test | Treadmill run to exhaustion, one hour after the last injection |
| Result | Treated mice ran about 70% longer and 45% further than vehicle mice |
| Housing | Chronic muscle studies were run at 30 °C (thermoneutrality), to keep the compound's effect on heat production out of the results |
The same paper reported more type IIa muscle fibres (the oxidative, fatigue-resistant kind), more mitochondrial markers and an exercise-like gene programme in muscle. A second 2-week study reported a rise in grip strength. In mice without ERRα in their muscle, the endurance gain disappeared, which is the evidence that the effect runs through that receptor.
Six mice per group, one strain, one sex, a laboratory route and a laboratory temperature. The experiment was built to test a mechanism, and it was never designed to estimate what a person would gain.
The fat-loss claim: mice on a high-fat diet
The metabolic paper (Billon 2024, PMID 37739806; full text PMC10801787) used the same 50 mg/kg twice a day, 8 to 10 male mice per group:
- Normal-weight mice, 28 days: no difference in body weight, no change in lean mass, less fat gained, fatty-acid burning up 25%, food intake unchanged.
- Diet-induced obese mice, 28 days: treated mice weighed about 12% less; vehicle mice gained about 5 g of fat against under 0.5 g on the drug.
- Genetically obese (ob/ob) mice, 12 days: body weight only trended down; fat mass and liver weight fell.
- Glucose tolerance in normal mice did not improve.
For a lifter, the line that matters is the lean-mass one. In the only 28-day study in normal-weight mice, SLU-PP-332 changed fuel use and fat gain and left lean mass where it was. The compound's effect in these papers is endurance and fat oxidation, with nothing reported on muscle size.
The census
PubMed, 2026-09-30. A search for SLU-PP-332 returns 10 records. Read one by one:
| Kind of record | Count | Notes |
|---|---|---|
| Mouse studies | 4 | Endurance (2023), ageing kidney (2023), heart failure (2024), metabolic syndrome (2024) |
| Chemistry papers | 2 | Successor compound SLU-PP-915 (2026), structure-activity analysis (2026) |
| Human muscle cells in a dish | 1 | Myoblasts from 10 inactive women having hip replacement (2025) |
| Anti-doping metabolism studies | 2 | UCLA and Cologne, human liver fractions (2026) |
| Review | 1 | Spanish-language systematic review of preclinical work (2026) |
| Human trials | 0 |
Six of the ten list Thomas Burris, the compound's developer, as an author. The one study using human tissue took muscle biopsies from 10 inactive women during hip surgery, grew the cells and treated them in culture; the cells showed less oxidative stress and formed more myotubes (Bonanni 2025, PMID 40692696). That result comes from cells in a dish, and no person received the compound. The 2026 review reaches the same place: the effects are preclinical and efficacy and safety in humans remain to be confirmed (de Souza-Lima 2026, PMID 42024694).
ClinicalTrials.gov, 2026-09-30. Searches for SLU-PP-332 (full text and intervention field) and for SLU-PP-915 return 0 studies. A control search for MOTS-c on the same day returned 9, so the search was working.
The detail sellers leave out: the developers say it is not orally available
In late 2025 Burris's laboratory published its successor, SLU-PP-915, and described the original plainly: SLU-PP-332 "improves aerobic performance in mice but lacks oral bioavailability" (Billon 2026, PMID 41421047). The newer compound was developed to fix that. Every published SLU-PP-332 result in a living animal used injection into the abdomen. A product taken by mouth has no published evidence behind it at all, including from the lab that made the molecule.
Who is behind the research
The papers disclose their interests, and the disclosures matter for how far the findings reach:
- 2023 endurance paper: three authors, including Burris, declared stock in Myonid Therapeutics, "which focuses on ERR based therapeutics".
- 2024 metabolic paper: three authors declared stock in Myonid Therapeutics and Pelagos Pharmaceuticals.
- 2026 SLU-PP-915 paper: SLU-PP-915 is Saint Louis University intellectual property with Burris as inventor; he holds stock in both companies.
The mouse data are published and peer-reviewed. What is missing is anyone outside the developing group reproducing the endurance result, in any species.
Status in sport
The brief for this page expected a named listing, and there isn't one. WADA's 2026 Prohibited List, read on 2026-09-30, names neither SLU-PP-332 nor ERR agonists. Section S4.4.1 names three metabolic-modulator families by example: AMPK activators (AICAR, MOTS-c, BAM15), PPARδ agonists (GW1516) and Rev-erbα agonists (SR9009, SR9011).
That does not make it permitted. Section S0 prohibits at all times "any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use," naming drugs under pre-clinical development as an example. An unapproved compound with no human trial fits that description on its face. The laboratories have not waited for a name on the List: UCLA's Olympic Analytical Laboratory identified 22 human-liver metabolites and eight candidate markers (Avliyakulov 2026, PMID 41688415), and the Cologne laboratory identified nine (Möller 2026, PMID 41588687), both explicitly for doping control. Section-by-section status for the other compounds is on WADA status by compound, and the testing picture is on peptides and drug testing.
Regulators: no approval anywhere found for this page, and openFDA's drug-approval database returned no match for the name on 2026-09-30.
What the mouse amounts would mean at human scale
The endurance and metabolic studies used 50 mg/kg twice a day by injection. The body-surface-area convention used to set first-in-human safety starting doses divides a mouse dose by about 12.3 (Nair and Jacob 2016, PMID 27057123). Applied here, 50 mg/kg becomes about 4.1 mg/kg per injection, roughly 325 mg twice a day for an 80 kg adult, or about 650 mg a day.
That is arithmetic about scale. It says nothing about an effective or a safe amount, and it describes an injected compound that its developers say does not work by mouth. No human dose has been studied. Peptifact's pages on what circulates as SLU-PP-332 dosing and its reported side effects cover the market figures and the adverse-event record.
How it sits next to the other "exercise mimetics"
SLU-PP-332 follows the same path as MOTS-c: a striking mouse endurance result, published by a group with a commercial stake, then onto the grey market with no human trial. MOTS-c at least has one registered human study. The older example, AICAR, is covered on peptides for endurance, and the fat-loss comparisons are on peptides for fat loss.
The honest summary
- A synthetic small molecule, not a peptide; activates ERRα, β and γ.
- 10 PubMed records, 0 human trials, 0 registry entries; 6 of the 10 co-written by its developer.
- The "70% longer" run: six male mice per group, injected twice a day for about a week.
- In normal-weight mice over 28 days, lean mass did not change.
- Its developers state it lacks oral bioavailability.
- Not named on WADA's 2026 List. S0's wording on unapproved drug candidates describes it, and two anti-doping labs already have detection methods.
Limits of this page
PubMed and registry counts depend on query wording and were taken on one date. The 70% and 45% figures are the paper's own rounded statements of a bar chart, and the underlying group means and variances were not read from raw data. Whether a sanctioning body would charge SLU-PP-332 under S0 or read it into S4.4 is a question for that body; this page reports the List's wording, not a legal opinion. WADA publishes each year's List in the autumn for the following January, and the 2027 List may name compounds the 2026 one does not.
Sources and dates
- 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;18:756–71 — PMID 36988910, full text PMC11584170 read 2026-09-30 incl. methods, Figure 2 legend and competing interests
- Billon C, Schoepke E, Avdagic A, et al. A synthetic ERR agonist alleviates metabolic syndrome. J Pharmacol Exp Ther 2024;388:232–40 — PMID 37739806, full text PMC10801787 read 2026-09-30
- 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;393:103787 — PMID 41421047
- Xu W, Billon C, Li H, et al. Novel pan-ERR agonists ameliorate heart failure. Circulation 2024;149:227–50 — PMID 37961903
- Wang XX, et al. Estrogen-related receptor agonism reverses mitochondrial dysfunction and inflammation in the aging kidney. Am J Pathol 2023;193:1969–87 — PMID 37717940
- Bonanni R, et al. Targeting ERRs to counteract age-related muscle atrophy associated with physical inactivity: a pilot study. Front Physiol 2025;16:1616693 — PMID 40692696
- Okda HE, et al. Chemical optimization of the exercise mimetic SLU-PP-332. Int J Biol Macromol 2026;355:151450 — PMID 41850449
- Avliyakulov NK, Sobolevsky T, Ahrens E. In vitro metabolites of exercise mimetic SLU-PP-332 for doping-control purposes. Drug Test Anal 2026;18:439–50 — PMID 41688415
- Möller T, Krug O, Thevis M. In vitro metabolism and analytical characterization of SLU-PP-332 and SLU-PP-915. Rapid Commun Mass Spectrom 2026;40:e70039 — PMID 41588687
- de Souza-Lima J, et al. Pharmacological activation of ERRα/β/γ as an exercise mimetic (in Spanish). Rev Med Chil 2026;154:237–45 — PMID 42024694
- Nair AB, Jacob S. A simple practice guide for dose conversion between animals and human. J Basic Clin Pharm 2016;7:27–31 — PMID 27057123
- PubMed, searched 2026-09-30:
SLU-PP-332→ 10 records, all abstracts read. - ClinicalTrials.gov API v2, searched 2026-09-30:
SLU-PP-332(term and intervention) → 0;SLU-PP-915→ 0; controlMOTS-c→ 9. - World Anti-Doping Agency, 2026 Prohibited List, sections S0 and S4.4 read 2026-09-30.
- openFDA drugs@FDA endpoint, queried 2026-09-30 for
SLU-PP-332→ no match.