SLU-PP-332

SLU-PP-332, also written SLU PP 332 and described in the press as an exercise mimetic or exercise in a pill, is a synthetic small-molecule agonist of the oestrogen-related receptors ERR alpha, beta and gamma. It is one of the newest and least characterised compounds sold for research, with published data in cells and mice only. This page lists every brand of SLU-PP-332 stocked at Free Muscle, compared on strength per capsule, capsules per pack and whether a batch certificate is available. Sold for laboratory research to adults only.

What is SLU-PP-332?

The oestrogen-related receptors are three orphan nuclear receptors, ERR alpha, ERR beta and ERR gamma. Despite the name they do not bind oestrogen. They regulate the expression of genes for mitochondrial biogenesis, fatty acid oxidation and oxidative metabolism, and their activity rises in skeletal muscle in response to endurance exercise. SLU-PP-332 was developed at Saint Louis University, which is where the SLU prefix comes from, as a pan-agonist that switches on all three receptors. It was designed as a tool compound to test whether pharmacological activation of ERRs could reproduce part of the adaptive response to aerobic training.

The first pharmacology paper appeared in 2023, so the entire literature is only a few years old and comes largely from the discovering group and its collaborators. Follow-up work has explored the compound in mouse models of obesity and metabolic syndrome, heart failure and kidney ageing, and a successor compound, SLU-PP-915, has since been described. SLU-PP-332 has never entered a clinical trial. There is no human pharmacokinetic, safety or efficacy data of any kind, and it is not approved as a medicine anywhere in the world. Anyone claiming a human result for this compound is not citing published evidence.

What the published research reports

• Exercise response and endurance in mice (2023). In cultured muscle cells and in mice, SLU-PP-332 activated ERR alpha-dependent gene programmes resembling the acute response to aerobic exercise. Treated mice showed a higher proportion of oxidative type IIa muscle fibres and ran further and for longer in treadmill tests than controls. The effect was lost in mice lacking ERR alpha. The study reported no adverse-event data and did not address long-term safety. Billon C, et al. Synthetic ERR alpha/beta/gamma agonist induces an ERR alpha-dependent acute aerobic exercise response and enhances exercise capacity. ACS Chem Biol. 2023;18(4):756-771. PMID: 36988910.
• Metabolic syndrome models in mice (2024). In diet-induced and genetically obese mice, treatment increased energy expenditure and fat oxidation and reduced fat mass, with improvements in glucose handling, without a change in food intake. The authors describe the changes as resembling the effects of exercise training. The work remained entirely in rodents. Billon C, et al. A synthetic ERR agonist alleviates metabolic syndrome. J Pharmacol Exp Ther. 2024;388(2):232-240. PMID: 37739806.
• Metabolism and detection for anti-doping (2026). Anti-doping analytical chemists characterised the in vitro metabolism of SLU-PP-332 and SLU-PP-915 using liver enzyme preparations and mass spectrometry, identifying nine metabolites of SLU-PP-332 and describing the compounds as having doping potential. This is analytical work aimed at detection and says nothing about efficacy or safety. Moller T, et al. 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.

Every efficacy result above comes from mice, most of it from a single research group, and the doses were set per kilogram of animal body weight in ways that do not translate to a capsule. Nothing is known about human tolerability, off-target effects or long-term exposure. None of the above is a claim about any product on this page.

Brands of SLU-PP-332 we stock

• BioLab Metabolic Boost (SLU-PP-332) 100 mcg, 60 capsules. 100 micrograms per capsule, 60 capsules, 6 mg of compound per pack. View BioLab 100 mcg.
• BioLab Metabolic Boost (SLU-PP-332) 200 mcg, 60 capsules. 200 micrograms per capsule, 60 capsules, 12 mg per pack. View BioLab 200 mcg.
• BioLab Metabolic Boost (SLU-PP-332) 500 mcg, 60 capsules. 500 micrograms per capsule, 60 capsules, 30 mg per pack. View BioLab 500 mcg.
• Thoroughbred Labs SLU-PP-332, 60 capsules. Capsule form, 60 capsules per pack. The per-capsule strength is not stated in our listing data, so check the label detail on the product page before comparing. View Thoroughbred Labs SLU-PP-332.

Both brands are third-party manufacturers. For each, a batch certificate of analysis is shown on the listing only where the manufacturer has supplied one for the batch we hold, and is not shown otherwise. Free Muscle does not currently make its own SLU-PP-332.

How to compare them

These are microgram strengths, so the arithmetic matters more than usual. Multiply micrograms per capsule by capsules per pack to get total compound, then divide the price by that figure for a cost per milligram. The 100 mcg and 500 mcg BioLab packs contain the same number of capsules but differ five-fold in compound. Where a listing does not state a strength, treat the pack as unquantified until you have seen the certificate. Then check who tested the batch, the method and whether the batch number matches the pack.

Batch testing and certificates of analysis

A certificate of analysis (COA) for a research compound reports identity, confirming that the material is SLU-PP-332, and purity, the proportion of the sample that is the compound, typically by HPLC with mass spectrometry to confirm identity. A good certificate names the laboratory, method, batch number and date. For a compound this new, identity testing is especially important.

For BioLab and Thoroughbred Labs we show a certificate only where the manufacturer supplies one for the batch we hold. A generic PDF with no batch number, no date or no named laboratory is not a batch certificate. Free Muscle brand products are assayed by Janoshik Analytical for every batch, with certificates available by email on request. See our lab testing page for how to read one.

Legal status in the UK

SLU-PP-332 is not a licensed medicine in the UK. The MHRA has not assessed it, it has never been through a clinical trial, and it is not an authorised food supplement or a permitted novel food. It is supplied by Free Muscle for laboratory research to adults aged 18 or over, and not for human consumption.

For sport, SLU-PP-332 is not yet named on the WADA Prohibited List, but section S4.4, metabolic modulators, covers activators of AMPK and PPAR delta agonists together with other substances with a similar biological effect, and anti-doping laboratories have already published detection methods for SLU-PP-332 metabolites. Anyone subject to anti-doping rules should assume it is treated as prohibited. Our SARMs research guide explains how the UK regulates unlicensed research compounds in general.

Storage and handling

Keep the container tightly sealed in a cool, dry place away from direct light and heat. Keep the batch number with the material, do not transfer capsules into unlabelled containers, and handle in line with good laboratory practice. Keep out of the reach of children and animals.

Delivery and returns

Free Muscle is a UK company, FreeMuscle LTD, based in Scunthorpe. Every order ships with free tracked UK delivery in plain packaging. Orders placed before 2pm Monday to Friday are processed the same working day. EU delivery takes 3 to 7 working days. Unopened items can be returned within 30 days. Customers must be 18 or over. See shipping and our guarantee for the full terms.

Related reading

• What Are SARMs? The 2026 Research Guide
• How to Read a Certificate of Analysis (COA)
• Price per milligram: the only honest way to compare
• Muscle Market is live: five brands, one basket, one parcel

Related collections: 5-Amino-1MQ, Cardarine (GW-501516), SR9009 (Stenabolic), BioLab, Thoroughbred Labs.

All products on this page are supplied for laboratory research use only. SLU-PP-332 is not a licensed medicine, has no human data and has not been evaluated by the MHRA, EMA or FDA. It is not a food supplement and is not for human consumption. You must be 18 or over to order. Nothing on this page is medical or dosing advice.

Research guides

• SLU-PP-332 and 5-Amino-1MQ: what the mouse data show