SLU-PP-332 Capsules UK

SLU-PP-332, also written SLU PP 332 (sometimes misspelt SLU-PP-322) and called an exercise mimetic or exercise in a pill in the press, is a synthetic small-molecule agonist of the oestrogen-related receptors ERR alpha, beta and gamma, not a peptide. It is one of the newest and least characterised research compounds, with data from mice and cultured cells, including human muscle cells, but none from people. 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.

Chemically it is an acylhydrazone. A certificate of analysis may name it by the chemical name or CAS number below, from PubChem (checked October 2026), rather than as SLU-PP-332.

In the developers' cell assays it activated ERR alpha at the lowest concentration (EC50 98 nM), then ERR beta (230 nM) and ERR gamma (430 nM): a pan-agonist with a modest ERR alpha preference. These are cell culture figures, not effects in animals or people.

Route matters for a capsule listing. The 2023 exercise study and the 2024 heart failure study gave it to mice by intraperitoneal injection, and its developers reported in 2026 that it is not bioavailable by mouth (see below). No study has tested it in capsule form, and we make no claim about what the capsules listed here do.

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, injected intraperitoneally, 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. A 10-day screen found no overt toxicity (normal blood counts and electrolytes, no significant change in creatine kinase), a short check rather than a toxicology study; long-term safety was not addressed. Three authors declared stock in Myonid Therapeutics, an ERR therapeutics company. 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 improved insulin sensitivity, 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.
• Heart, kidney and human muscle cells (2023 to 2025). In mice with pressure-overload heart failure, SLU-PP-332 and SLU-PP-915 improved ejection fraction, reduced fibrosis and increased survival (Xu et al., 2024; one author co-founded Pelagos Pharmaceuticals). In 21-month-old mice, eight weeks of treatment reversed the age-related rise in albuminuria, podocyte loss and inflammatory cytokines (Wang et al., 2023). Muscle cells from ten inactive women, treated in a dish, showed lower markers of oxidative stress and senescence (Bonanni et al., 2025); no person received the compound. Xu W, 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. Wang XX, 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. 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.
• Metabolism and detection for anti-doping (2026). Two anti-doping laboratories have mapped its metabolism with human liver preparations and mass spectrometry: the Cologne group found nine metabolites of SLU-PP-332 and described it and SLU-PP-915 as having doping potential, and the UCLA Olympic Analytical Laboratory found 22, naming the most abundant as targets for doping control. This is detection work 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. Avliyakulov NK, et al. Analysis and identification of in vitro metabolites of exercise mimetic SLU-PP-332 ERR alpha/beta/gamma agonist for doping-control purposes. Drug Test Anal. 2026;18(3):439-450. PMID: 41688415.
• Oral activity and a successor compound (2026). Writing about their earlier compound, the developers stated that SLU-PP-332 is not orally bioavailable, then described SLU-PP-915, a chemically distinct pan-ERR agonist that worked in mice when given by mouth. The senior author is listed as an inventor of SLU-PP-915, which the university owns as intellectual property, and holds stock in Myonid Therapeutics and Pelagos Pharmaceuticals, both developing ERR agonists. Billon C, et al. 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.

Every efficacy result above comes from mice or from cells in culture, most of it from the developers and their collaborators, 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. Thoroughbred Labs states 250 mcg per capsule, which is 15 mg per pack. 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. Check the units too: certificates may report milligrams where labels use micrograms (1 mg is 1,000 mcg). The comparison table above this guide already shows total milligrams and price per milligram for each listing.

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. A mass spectrometry identity result should match a molecule of about 290 g/mol, and the certificate may use the chemical name or CAS number shown above; a peptide content figure does not apply to this small molecule.

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.

Where to buy SLU-PP-332 in the UK: how to check a supplier

Whichever shop you buy SLU-PP-332 from, check these five points before you order:

1. A batch number and a certificate for that batch. The pack should carry a batch number, and the seller should be able to show a certificate of analysis for that same batch from a named laboratory, with the test date. For BioLab and Thoroughbred Labs, a certificate is shown where the brand supplies one for the batch we hold.
2. The strength per capsule and the capsule count. With both figures you can work out the total milligrams in the pack and the price per milligram; the comparison table above does this for every listing here that states both. If a listing does not state one of them, ask the seller before you order.
3. Research-use labelling and an age check. A research compound should be sold for laboratory research use only, not for human consumption, to adults aged 18 or over, with no dosing or usage advice. That is how every listing here is sold.
4. Prices in pounds sterling and tracked UK dispatch. UK delivery from us is free and tracked on every order, with no minimum spend, and usually arrives 2-3 working days after dispatch; orders placed before 2pm Monday to Friday are processed the same working day.
5. A clear returns policy. Unopened items can be returned to us within 30 days.

Brands on this page: BioLab and Thoroughbred Labs. The UK supplier checklist and how we test go into more detail.

Legal status in the UK

Where SLU-PP-332 stands, checked in October 2026:

• Medicines: not a licensed medicine in the UK and not approved as a medicine anywhere; the MHRA has not assessed it.
• Controlled drugs: not a controlled drug under the Misuse of Drugs Act 1971.
• Food: not an authorised food supplement or a permitted novel food.
• Clinical trials: none published and none registered on ClinicalTrials.gov.
• Sport: covered by section S0 of the WADA Prohibited List, and so prohibited at all times (see below).
• Supply: sold by Free Muscle for laboratory research to adults aged 18 or over, not for human consumption.

For sport, SLU-PP-332 is not named on the 2026 WADA Prohibited List, but that does not make it permitted. Section S0 prohibits at all times, in and out of competition, any pharmacological substance that no other section addresses and that has no current approval for human therapeutic use, such as drugs in pre-clinical development; SLU-PP-332 is approved nowhere. The metabolic modulators section, S4.4, lists AMPK activators, PPAR delta agonists and Rev-erb alpha agonists alongside insulins, meldonium and trimetazidine, but not ERR agonists. In 2026 two anti-doping laboratories published metabolites to target for its detection. Our SLU-PP-332 and 5-Amino-1MQ research guide covers both compounds in more depth.

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 the trading name of FreeMuscle, a business registered in Andorra, with UK operations and dispatch 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

• SLU-PP-332 and 5-Amino-1MQ: what the mouse data show
• SR9009 (Stenabolic): REV-ERB research and the bioavailability problem
• How to Read a Certificate of Analysis (COA)
• Price per milligram: the only honest way to compare
• How to choose a SARMs or peptide supplier in the UK: a checklist

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

Research compounds sold by Free Muscle are supplied for laboratory research use only and are not for human consumption. They are not authorised as medicines by the MHRA, EMA or FDA, are not food supplements, and are sold only to adults aged 18 or over. Nothing on this page is medical or dosing advice.

Research guides

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