If you have gone looking for SLU-PP-332 research in the last year, you have probably read that it is an "exercise in a pill" compound. The more useful — and much less flattering — story is buried in the medicinal chemistry literature: in 2026 the same academic groups that created SLU-PP-332 published a full structure–activity analysis of its scaffold, and the paper reads less like a victory lap than a list of repairs. Moderate metabolic stability. Low ligand efficiency. Poor solubility. A benchmark probe, not a drug candidate. That framing matters for Australian readers, because what is being sold online under this name is being marketed as if the molecule were finished. It isn't.

Before anything else, a correction this site keeps making: SLU-PP-332 is not a peptide. It is a small-molecule pan-agonist of the estrogen-related receptors ERRα, ERRβ and ERRγ — orphan nuclear receptors that sit upstream of mitochondrial biogenesis, fatty acid oxidation and the Krebs cycle. It ended up filed under "peptides" by vendors and forums, and the label stuck. Our full profile lives at /peptides/slu-pp-332, alongside the rest of the peptides library.

What the 2026 SAR paper actually says

The original in vivo work (Billon and colleagues, ACS Chemical Biology, 2023) showed that SLU-PP-332 given intraperitoneally to mice at 50 mg/kg induced an ERRα-dependent acute aerobic exercise gene programme in skeletal muscle and increased treadmill running distance and time to exhaustion against vehicle controls. Group sizes were small (n = 6 per arm). That result is genuine and mechanistically coherent — it is also the high-water mark of the evidence.

The 2026 optimisation study (published in the International Journal of Biological Macromolecules) went back to the scaffold and asked whether it was drug-like. The reported answer: SLU-PP-332 shows microsomal stability of roughly t½ = 31.3 minutes with intrinsic clearance around 22 µL/min/mg, and ligand efficiency values of 0.42 (ERRα) and 0.31 (ERRγ) — numbers the authors themselves flag as the reason structural improvement was needed. Analogues in that series, including one designated BE2180 with a quinoline substitution, achieved comparable transcriptional output with lower lipophilicity, better solubility and longer microsomal half-life.

Read that in plain terms: the molecule works well enough to interrogate ERR biology in a dish and in a mouse. It was never designed to survive a human liver, a human gut, or a dosing schedule measured in months.

The oral bioavailability problem nobody advertises

The single most commercially relevant fact about SLU-PP-332 is that it is not orally bioavailable. Every published efficacy experiment used injection. The Burris group's response was not to dose it harder — it was to build a different molecule. SLU-PP-915, reported in the Journal of Pharmacology and Experimental Therapeutics, is a chemically distinct ERR pan-agonist engineered around a boronic acid moiety for oral activity. Given orally to mice, it enhanced running distance and duration to an extent comparable with intraperitoneal SLU-PP-332 once systemic exposure was accounted for, and induced the canonical ERR targets PGC-1α, LDHA, PDK4 and DDIT4 in muscle.

So if you encounter SLU-PP-332 sold as an oral capsule or a sublingual, the pharmacology says it is the wrong molecule for that route. The oral one is 915 — and 915 is also mouse-only, with no human trials of its own.

Is SLU-PP-332 legal in Australia?

Here is the local picture, and it is genuinely unusual.

SLU-PP-332 is not currently scheduled in the Poisons Standard. The entry people often point to — SR9009 (stenabolic) — covers REV-ERB agonists, a different receptor family with a different mechanism. Being unscheduled is not the same as being permitted: there is no lawful pathway for therapeutic supply of SLU-PP-332 in Australia. It is not on the ARTG, no sponsor has sought TGA evaluation, and with zero registered human trials there is nothing for a prescriber to work from. Material circulating locally is sold as a laboratory reagent, "not for human consumption" — a label that describes a legal position, not a safety assessment.

For anyone in sport, the position is much simpler. WADA's S0 catch-all prohibits any pharmacological substance with no current approval by a government health authority for human therapeutic use — which is precisely what SLU-PP-332 is. And detection is no longer theoretical: two separate 2026 analytical papers, in Rapid Communications in Mass Spectrometry and Drug Testing and Analysis, characterised the in vitro metabolites of SLU-PP-332 (and 915) specifically for doping-control purposes. Athletes under Sport Integrity Australia's jurisdiction should assume testability.

The registry trap

If you search clinical trial registries for this compound, be careful. ClinicalTrials.gov currently hosts fictional demonstration records for several peptides and research compounds — often listing a non-existent sponsor such as "Hudson Biotech" with a RECRUITING status. Check that the sponsor is a real organisation before treating any registry entry as evidence. As of this writing, there are no legitimate registered human trials of SLU-PP-332.

What a careful reader should take from this

The ERR hypothesis is one of the more interesting ideas in metabolic pharmacology: activate the transcriptional programme that endurance exercise switches on, and you may address mitochondrial dysfunction in obesity, heart failure, sarcopenia and steatohepatitis. The preclinical data supporting that idea in mice are real.

What does not follow is that a tool compound with a 31-minute microsomal half-life, no oral activity and no human exposure data is ready to be used by people. Its own inventors have spent three years building replacements. That is the most informative signal in the entire file.

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FAQ

What is SLU-PP-332?

SLU-PP-332 is a synthetic small molecule — not a peptide — that acts as a pan-agonist of the estrogen-related receptors ERRα, ERRβ and ERRγ. It has been studied as an "exercise mimetic" in mice, where injection increased treadmill running distance, but it has never been tested in humans.

Is SLU-PP-332 legal in Australia?

It is not currently scheduled in the Poisons Standard, but it is also not on the ARTG and has no lawful pathway for therapeutic supply in Australia. The SR9009 scheduling entry covers REV-ERB agonists, which are a different compound family.

Does SLU-PP-332 work orally?

No. Published work consistently describes SLU-PP-332 as lacking oral bioavailability, which is why its developers created SLU-PP-915 — a chemically distinct, orally active ERR agonist. SLU-PP-915 is also mouse-only with no human trials.

Is SLU-PP-332 detectable in drug testing?

Yes. Two 2026 analytical papers characterised its in vitro metabolites specifically for anti-doping purposes, and WADA's S0 catch-all category prohibits substances with no approval for human therapeutic use.

Sources

This article is information only, not medical advice. SLU-PP-332 is an unapproved investigational compound with no registered human trials and no approved therapeutic use in Australia or anywhere else. retatrutide.net.au is independent and does not sell or source any compound.