Educational reference, not medical advice. This page summarizes information from published research and regulatory filings for educational purposes. It is not a recommendation to use any compound and should not replace guidance from a licensed healthcare provider. Most peptides discussed here are not approved for the uses described.
What it is
SLU-PP-332 is a small synthetic molecule, not a peptide, developed by the Burris laboratory while at Saint Louis University (the "SLU" in the name) and later continued at the University of Florida. It is a pan-agonist of the three estrogen-related receptors — ERRα, ERRβ, and ERRγ — orphan nuclear receptors that regulate mitochondrial biogenesis, oxidative metabolism, and fatty acid oxidation in skeletal muscle, heart, and other high-energy tissues. ERR transcriptional activity rises with exercise, and pharmacological activation of these receptors has been described in the literature as an "exercise mimetic" approach.
The molecule has attracted attention in popular press as a potential "exercise in a pill," though that framing far outruns the underlying data.
History
The Burris lab published the discovery paper for SLU-PP-332 in ACS Chemical Biology in 2023 (Billon et al.), describing the compound as a pan-ERR agonist that triggers an acute aerobic-exercise-like transcriptional response in mouse skeletal muscle. Treated mice showed increased exercise capacity and mitochondrial biogenesis. Follow-up work in 2023–2024 reported that the compound reduced body weight and improved insulin sensitivity in obese mice, ameliorated heart failure in rodent models, and reversed mitochondrial dysfunction in aged kidneys.
A successor molecule, SLU-PP-915, with improved oral bioavailability, was disclosed in 2026 in the same line of work. Neither compound has been tested in humans.
Regulatory status
SLU-PP-332 has no approved use in any country. It is not a peptide, so it does not fall under the FDA's 503A bulk substances list, but it is not an approved drug, an authorized investigational drug, or a compounded substance. It is sold strictly as a research chemical with not-for-human-use labeling. There is no validated supply chain.
The World Anti-Doping Agency added pan-ERR agonists to its prohibited list under the S4 (hormone and metabolic modulators) category in 2024, anticipating that exercise-mimetic compounds could be used in competitive sport.
How researchers describe its action
The published mechanism papers describe SLU-PP-332 as a direct agonist of all three ERR isoforms with the following downstream effects in rodents:
- Activation of the ERRα transcriptional program, which drives expression of mitochondrial biogenesis genes and oxidative phosphorylation components.
- Increased fatty acid oxidation in skeletal muscle and heart, with reduced reliance on carbohydrate oxidation.
- Increased exercise capacity in untrained mice, measured by treadmill performance and time to exhaustion.
- Improved metabolic markers in obese mice — reduced body weight, improved glucose tolerance, lower hepatic fat — without changes in food intake.
Whether these effects translate to humans, and at what doses, is not known. ERRα has broad tissue expression and chronic pan-agonism has not been characterized for safety in humans.
Half-life and dosing intervals
The published pharmacokinetic data is limited to rodents. In mice, SLU-PP-332 has a circulating half-life of approximately 3 to 4 hours after intraperitoneal injection. Oral bioavailability is poor, which is part of why the successor molecule SLU-PP-915 was developed. In published efficacy studies, mice received doses of approximately 25 mg/kg twice daily via intraperitoneal injection.
There is no validated human dose. Online observational use of unverified material is not supported by clinical evidence.
Reconstitution example
Research-grade SLU-PP-332 is supplied as a powder, often dissolved in DMSO or a DMSO/PEG vehicle for laboratory use because the molecule has poor aqueous solubility. It is typically supplied in 5 mg or 10 mg quantities.
It is not a peptide and is not validated for subcutaneous injection in humans. Vial's calculator is designed for lyophilized peptides reconstituted in bacteriostatic water and does not apply to small molecules dissolved in DMSO.
What to know
- Not a peptide. SLU-PP-332 is a small molecule. It is grouped with research peptides in some online marketplaces but its pharmacology, formulation, and regulatory profile are different.
- Preclinical only. All efficacy claims come from mouse studies. There are no published human trials.
- Poor oral bioavailability. The molecule was developed for laboratory use, and the published efficacy doses are intraperitoneal in mice. The successor compound SLU-PP-915 was designed to address this.
- Banned in competition. Pan-ERR agonists are on the WADA prohibited list.
- Long-term safety unknown. ERRα is expressed in many tissues; chronic systemic activation has not been characterized in humans.
- Storage. Stable as a dry powder at room temperature; protect from moisture and light. Solutions in DMSO are typically stored frozen.
Sources
- 1.Billon C et al. (2023). Synthetic ERRα/β/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity. ACS Chemical Biology.
- 2.Billon C et al. (2024). A Synthetic ERR Agonist Alleviates Metabolic Syndrome. Journal of Pharmacology and Experimental Therapeutics.
- 3.Xu W et al. (2024). Novel Pan-ERR Agonists Ameliorate Heart Failure Through Enhancing Cardiac Fatty Acid Metabolism and Mitochondrial Function. Circulation.
- 4.Wang XX et al. (2023). Estrogen-Related Receptor Agonism Reverses Mitochondrial Dysfunction and Inflammation in the Aging Kidney. American Journal of Pathology.