Most compounds get a doping test after someone gets caught using them. SLU-PP-332 has gone the other way round. In 2026, two separate anti-doping laboratories published detection chemistry for a molecule that has never been given to a human being in a registered trial — not once. If you've been searching "what is SLU-PP-332" or "SLU-PP-332 research", that inversion is the most informative thing in the current literature: the testing infrastructure is more developed than the efficacy evidence.

This post covers what those two 2026 papers actually did, why they matter more to Australian athletes than to anyone else, and what the underlying science still hasn't shown. Our full profile lives at /peptides/slu-pp-332.

First, the correction: SLU-PP-332 is not a peptide

It gets filed under "peptides" almost everywhere online, including in our own peptides index, because that's how people search for it. But it isn't one. SLU-PP-332 is a small synthetic molecule — a pan-agonist of the estrogen-related receptors ERRα, ERRβ and ERRγ, nuclear receptors that sit upstream of mitochondrial biogenesis and fatty-acid oxidation. No amino-acid chain, no injectable peptide pharmacology, no shared safety profile with anything in the GLP-1 or growth-factor families.

That distinction isn't pedantry. It changes how the compound is metabolised, how it's detected, and which regulatory categories it falls into. Anyone reasoning about SLU-PP-332 by analogy to peptides is reasoning from the wrong template.

The evidence base, stated plainly: mice

The foundational work is Billon and colleagues from the Burris lab at Saint Louis University, published in ACS Chemical Biology in 2023. In mice, SLU-PP-332 switched on an ERRα-dependent acute aerobic exercise gene programme in skeletal muscle and increased treadmill running distance and time versus vehicle controls. Dosing was intraperitoneal — injected into the abdominal cavity — because the original compound has poor oral bioavailability and a short exposure window. That's precisely why the same group went on to develop SLU-PP-915, the orally bioavailable successor.

What that body of work does not contain: any human dosing, any human safety data, any human endurance or body-composition outcome, and any long-term data on chronically activating a transcription factor family that governs mitochondrial output across the heart, liver and brain as well as muscle. The mouse work is interesting and it is real. It is also, three years on, unreplicated in our species.

What the 2026 detection papers found

Two groups published independently this year, using slightly different approaches, and their convergence is the story.

The Cologne study

Möller, Krug and Thevis at the Center for Preventive Doping Research characterised both SLU-PP-332 and SLU-PP-915 by liquid chromatography–high-resolution tandem mass spectrometry, generating metabolites using human liver S9 fraction and human liver microsomes, and confirming selected SLU-PP-915 metabolite structures by NMR. They reported nine metabolites for SLU-PP-332 — six phase-I products and three phase-II conjugates — and seven for SLU-PP-915, all phase-I.

The second group

A parallel paper by Avliyakulov, Sobolevsky, Ahrens and colleagues in Drug Testing and Analysis mapped an even wider transformation profile for SLU-PP-332: five monohydroxylated metabolites, three dihydroxylated, four reduced dihydroxylated, plus glucuronidated and sulfated conjugates involving the naphthalene and phenolic rings.

Two points follow. First, these are in vitro studies — liver fractions in a tube, not urine from dosed humans. The definitive target markers will only be pinned down when real samples appear. Second, and more practically: profiling SLU-PP-915 alongside SLU-PP-332 means the obvious workaround — switch to the successor compound — was closed off in the same publication cycle. The labs anticipated it.

Is SLU-PP-332 legal in Australia?

This is where Australian readers need two separate answers, because "legal" and "available" aren't the same question.

Poisons Standard status. SLU-PP-332 is not specifically scheduled in Australia. A recurring myth online is that the SR9009 (stenabolic) entry captures it — it doesn't. SR9009 is a REV-ERB agonist, a structurally and mechanistically different family. That's a different receptor, a different target class, a different entry.

But unscheduled does not mean supplyable. With no approval from any regulatory authority anywhere on earth, SLU-PP-332 has no lawful pathway for therapeutic supply in Australia. It is not on the ARTG. No Australian doctor can lawfully prescribe it as a therapeutic good, and marketing it for human use would engage therapeutic goods advertising provisions regardless of scheduling. Unscheduled is a gap in a list, not a permission.

Anti-doping is the unambiguous part. Sport Integrity Australia applies the WADA Prohibited List, and the S0 category — non-approved substances — captures any pharmacological substance with no current approval by any governmental regulatory health authority for human therapeutic use. SLU-PP-332 has no such approval, so S0 applies on that basis alone: prohibited at all times, in and out of competition. There is no therapeutic use exemption pathway for a compound that has never been trialled in humans.

For any Australian competing under a WADA-code sport — which in practice includes club-level athletes in national sporting organisations, not just elite competitors — the 2026 detection work removes the last practical ambiguity. The methods now exist.

What this means if you're following the space

The honest summary is that SLU-PP-332 is a well-characterised research tool with a genuinely interesting mechanism and an evidence base that stops at the rodent. The interesting near-term signal to watch isn't a new mouse study — it's whether SLU-PP-915 or a related ERR agonist ever enters a registered Phase 1. Until that happens, everything written about human dosing, human endurance gains or human fat oxidation for this compound is extrapolation from mice.

One caution while you're searching: clinical trial registries can host demonstration or unverified records. Before treating any "recruiting" trial as evidence, check that the listed sponsor is a real, identifiable organisation.

We track ERR agonists and the wider peptide and small-molecule research space as the primary literature moves. Join the free updates list if you want the next development without the marketing layer.

FAQ

Is SLU-PP-332 a peptide?

No. It's a small synthetic molecule that activates the estrogen-related receptors ERRα, ERRβ and ERRγ. It's commonly filed under "peptides" online because of how people search, but it shares no structural or pharmacological category with peptides.

Is SLU-PP-332 legal in Australia?

It isn't specifically scheduled in the Poisons Standard — the SR9009 entry covers REV-ERB agonists, a different compound family. But it has no approval anywhere in the world and no lawful therapeutic supply pathway in Australia, and WADA's S0 catch-all prohibits it in sport at all times.

Are there any human trials of SLU-PP-332?

None. As of September 2026 the published evidence is mouse-only, anchored to the 2023 Burris-lab work. No registered human efficacy or safety trial has reported results.

Can drug tests detect SLU-PP-332?

Yes — two anti-doping laboratories published LC–HRMS/MS detection chemistry and metabolite profiles in 2026, covering both SLU-PP-332 and its successor SLU-PP-915. Those studies used human liver fractions in vitro, so final urinary target markers will be refined once real samples are analysed.

Sources

This article is independent information, not medical advice. SLU-PP-332 is an investigational research compound with no human trials and no regulatory approval in Australia or anywhere else; retatrutide.net.au sells nothing and does not direct readers to suppliers.