If you want to know how seriously the anti-doping world takes an "exercise in a pill" compound, don't read the hype — read the mass spectrometry. In the first nine months of 2026, two separate laboratory groups published in vitro metabolism studies on SLU-PP-332 for doping-control purposes. One reported 22 metabolites. The other reported nine. Both were building the same thing: a way to catch the compound in an athlete's sample. That is a strange place for a compound's human-relevant data to begin, and it's the most concrete SLU-PP-332 research development of the year — so this post walks through what the two papers actually found, why the numbers differ, and what it means for anyone asking "is SLU-PP-332 legal in Australia".

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

It gets sold and discussed alongside peptides, and it sits in our peptides library for that reason, but SLU-PP-332 is a synthetic small molecule — an agonist of the oestrogen-related receptors ERRα, ERRβ and ERRγ, developed as a pharmacological tool at Saint Louis University. No amino acid chain, no injectable-peptide pharmacology, different metabolism entirely. The full background sits on our SLU-PP-332 profile.

That distinction matters here for a practical reason: peptides are largely broken down by peptidases into fragments that look like ordinary body chemistry, which makes them hard to detect. A small molecule goes through liver enzymes and comes out as hydroxylated, glucuronidated and sulfated products with distinctive masses. Detectable, in other words — if someone does the work of mapping them. In 2026, two groups did.

Paper one: 22 metabolites, and eight worth targeting

Avliyakulov and colleagues, writing in Drug Testing and Analysis, ran SLU-PP-332 through Phase I and Phase II in vitro metabolism and reported 22 transformation products: five monohydroxylated (M1–M5), three dihydroxylated (M6–M8), four reduced dihydroxylated (M9–M12), direct glucuronidation (M13) and direct sulfation (M19) of the parent, plus a set of combined hydroxylation-and-conjugation products on the naphthalene or phenolic rings. They nominated eight — M1, M7, M9, M10, M13, M14, M19 and M20 — as the most abundant and therefore the most useful analytical targets.

Paper two: nine metabolites, and the successor compound too

Möller, Krug and Thevis, publishing in Rapid Communications in Mass Spectrometry in January 2026, characterised both SLU-PP-332 and its orally bioavailable successor SLU-PP-915 using LC–HRMS/MS, with human liver S9 fraction and human liver microsomes. They identified nine metabolites for SLU-PP-332 — six Phase I and three Phase II conjugates — and seven for SLU-PP-915, all Phase I only. Selected SLU-PP-915 metabolites were synthesised and confirmed by NMR.

Why the counts disagree, and why that isn't a scandal

Twenty-two versus nine looks like a contradiction. It mostly isn't. In vitro metabolite counts depend on the enzyme system used (S9 fraction versus microsomes versus hepatocytes), incubation time, cofactors present, and how aggressively a group calls a low-abundance peak a metabolite. Two labs can honestly produce different maps of the same molecule. What's more telling is the overlap in purpose: both papers exist because sports drug testing programs expect this class to be misused, and neither can tell you what SLU-PP-332 does in a living human body.

The uncomfortable point about "human data"

Human liver microsomes are human tissue. They are not humans. As of this writing there are still no published human trials of SLU-PP-332 — no pharmacokinetics, no dose-ranging, no safety database. The entire efficacy story remains rodent: improved treadmill endurance, reduced fat mass, better insulin sensitivity, and cardiac mitochondrial effects in mouse models, delivered by injection because SLU-PP-332 itself has poor oral bioavailability. That last limitation is precisely why the Burris lab developed SLU-PP-915, reported in 2025 as an orally active pan-ERR agonist with comparable exercise-mimetic activity in mice. A 2026 systematic review of pan-ERR agonists reached the obvious conclusion: promising preclinical signals, clinical trials still needed.

So the first peer-reviewed work involving human biological material and SLU-PP-332 was generated to detect it, not to assess whether it helps anyone. Worth sitting with.

SLU-PP-332 Australia: unscheduled, un-supplied, and prohibited in sport

Three separate questions get collapsed into one, so let's separate them.

Poisons Standard. SLU-PP-332 has no entry of its own in the Australian Poisons Standard. The commonly cited SR9009 entry covers REV-ERB agonists — a different receptor family with a different mechanism — and does not capture ERR agonists. Unscheduled is not the same as approved.

Therapeutic supply. There is no TGA-registered SLU-PP-332 product, no approved indication and no lawful route for therapeutic supply in Australia. Anything marketed for human use is being sold outside that framework, with the identity, purity and dose all unverified.

Sport. This is the sharpest edge. WADA's S0 (Non-Approved Substances) category prohibits, at all times, any substance with no current approval from any government health authority for human therapeutic use — which describes SLU-PP-332 exactly. The 2026 Prohibited List took effect on 1 January 2026 and Sport Integrity Australia administers it here. An athlete does not need to find SLU-PP-332 named on a list to test positive; S0 is a catch-all, and after 2026 the laboratories have published metabolite targets to go looking for. For any Australian competing under a WADA-compliant code, that combination — banned by default, now detectable — is the practical bottom line.

What would actually move this forward

A Phase 1 study. Not a metabolite map, not another mouse endurance curve: a first-in-human safety and pharmacokinetics trial, most plausibly in SLU-PP-915 rather than SLU-PP-332 given the oral bioavailability problem. Until then, every claim about what this compound does to human body composition or fitness is an extrapolation from rodents. If you're tracking whether that trial ever appears, join the free updates list — and treat registry listings with scepticism, since some peptide and small-molecule entries circulating online trace back to sponsors that don't exist as real organisations.

FAQ

Is SLU-PP-332 a peptide?

No. It's a synthetic small-molecule agonist of the oestrogen-related receptors ERRα, ERRβ and ERRγ, developed at Saint Louis University. It's frequently mislabelled as a peptide because of where it's sold and discussed.

Is SLU-PP-332 legal in Australia?

It has no entry of its own in the Poisons Standard, but there is no TGA-approved product and no lawful route for therapeutic supply. It is also prohibited in sport at all times under WADA's S0 non-approved substances category, enforced here by Sport Integrity Australia.

Can SLU-PP-332 be detected in a drug test?

Two 2026 in vitro studies published metabolite maps specifically for doping-control use — one reporting 22 transformation products and nominating eight as analytical targets, the other reporting nine. Detection methods therefore exist, though real-world sensitivity in athlete samples hasn't been publicly reported.

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

None published. All efficacy data is from mice, and the only human material involved so far is liver microsomes and S9 fraction used in test-tube metabolism studies, not living participants.

Sources

This article is independent information, not medical advice. SLU-PP-332 is an unapproved investigational small molecule with no TGA or FDA approval, no human trials, and no lawful therapeutic supply in Australia; it is prohibited in sport at all times. Speak with a qualified Australian health practitioner before making any health decision.