Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-26. ← Back to Evidence Library

SLU-PP-332: what the evidence says

Name: SLU-PP-332
Creator: Dr. Nova Reyes
Published: 2026-10-26

At a glance

What it is: a small-molecule drug, not a peptide, made at Saint Louis University. It switches on all three estrogen-related receptors (ERRα, β, γ), which control mitochondria and fat burning. It is sold as an "exercise in a pill." It is not related to estrogen hormones despite the name. ^R1

What the evidence says: in mice it increased oxidative muscle fibers and running endurance, raised energy use, cut fat and improved insulin sensitivity, and helped mice with heart failure and aging kidneys. ^{R1, R2, R3, R4} No human study has been published or registered.

Biggest risks: unknown in people. Its makers say it lacks oral absorption and developed SLU-PP-915 for that reason. ^R5

Rating


Human Human evidence	None
Animal Animal / lab evidence	Mouse endurance, obesity, heart-failure and aging-kidney studies ^{R1, R2, R3, R4}
Regulatory	Never approved · Not on FDA 503A or 503B bulk lists · WADA 2026: not named; anti-doping labs treat it as a prohibited-class candidate Caution ^{R6, R7, R8, R9}
Established human dose	None. Study details lists what studies used

Evidence verdict: Exercise endurance, fat loss, heart or kidney protection: Animal only (mice) · Any effect in people: No human data Card verdict: No human data (exercise-mimic & fat-loss claims rest on mouse studies only) Card note: Not a peptide; mouse data only, see page

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: the core papers come from the inventors (Burris and colleagues, now partly at Washington University) and collaborators. ^{R1, R2} Anti-doping labs have already published detection methods. ^{R9, R10}

What is it?

ERRs are "orphan" nuclear receptors that help muscle adapt to aerobic exercise. SLU-PP-332 is a synthetic switch for them. Related pages: MOTS-c, 5-Amino-1MQ, SS-31.

Does it work?

Animal Endurance (Billon 2023): mice had more type IIa oxidative fibers and ran longer; the effect depended on ERRα. ^R1
Animal Obesity (Billon 2024): in diet-induced obese and ob/ob mice it raised energy use and fat burning, cut fat gain and improved insulin sensitivity. ^R2
Animal Heart failure (Xu 2024): improved heart function in mouse models. ^R3
Animal Aging kidney (Wang 2023): reversed mitochondrial and inflammation changes in old mice. ^R4
Animal Human muscle cells: a pilot lab study in muscle cells from inactive women. ^R11
Unknown No human trial.

Is it safe?

Unknown No human safety data.
Unknown Long-term effects of switching on ERRs throughout the body are unknown.

Gray-market "research use only" SLU-PP-332: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe. Gray-market products are often oral capsules, though the inventors report poor oral absorption. ^R5

What we don't know

Unknown Whether it does anything in people, at any amount
Unknown Safety in heart, liver and hormones over time

Is it legal?

US (FDA): never approved; no IND results published. Not on the 503A or 503B bulk lists, so there is no compounding route. ^{R6, R7}
Athletes: not named on the WADA 2026 list. WADA prohibits metabolic modulators (S4.4) and non-approved substances (S0); anti-doping chemists describe it as having doping potential. UNVERIFIED which section WADA would apply. ^{R8, R10}

Study details

These are amounts researchers used, not recommendations. | Study | People / model | Route | Amount used | Follow-up | Reported | Citation | |---|---|---|---|---|---|---| | Billon 2023 | Mice | Injection Caution route | UNVERIFIED amount not in abstract | Days–weeks | More oxidative fibers, longer running | [PMID 36988910](https://pubmed.ncbi.nlm.nih.gov/36988910/) | | Billon 2024 | Obese mice | Injection Caution | Caution not in abstract | ~1 month Caution | Less fat, better insulin sensitivity | [PMID 37739806](https://pubmed.ncbi.nlm.nih.gov/37739806/) |

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 26, 2026)

^R1 Billon C, et al. ACS Chem Biol. 2023. PMID 36988910
^R2 Billon C, et al. J Pharmacol Exp Ther. 2024. PMID 37739806
^R3 Xu W, et al. Circulation. 2024. PMID 37961903
^R4 Wang XX, et al. Am J Pathol. 2023. PMID 37717940
^R5 Billon C, et al. J Pharmacol Exp Ther. 2026. PMID 41421047
^R6 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R7 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R8 WADA. The 2026 Prohibited List, S4.4 and S0. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R9 Avliyakulov NK, et al. Drug Test Anal. 2026. PMID 41688415
^R10 Möller T, et al. Rapid Commun Mass Spectrom. 2026. PMID 41588687
^R11 Bonanni R, et al. Front Physiol. 2025. PMID 40692696

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use SLU-PP-332. Talk to a clinician you trust, especially if you have heart, liver or kidney disease, are pregnant, or are a tested athlete. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).