Guides May 12, 2026

SLU-PP-332: Not a Peptide, Strong Mouse Data, and No Human Trials

SLU-PP-332 is an ERR agonist sold by peptide vendors as an exercise mimetic, but it is a synthetic small molecule, not a peptide, and all efficacy data remain preclinical.

SLU-PP-332 is one of the cleanest examples of a compound being marketed to peptide buyers even though it is not actually a peptide.

That matters because almost every important question about it changes once you understand what it is:

the chemistry is different
the verification methods are different
the storage logic is different
the dosing assumptions are different
and the regulatory path is different

The compound itself is real.

The mouse data are real.

But the category most people encounter it through is still misleading.

What SLU-PP-332 actually is

SLU-PP-332 is a synthetic small molecule, not a peptide.¹²

Supplier pages from MedChemExpress and Tocris both list it as a low-molecular-weight chemical compound with:

CAS number: 303760-60-3
molecular formula: C18H14N2O2
molecular weight: 290.32 g/mol¹²

Tocris gives the chemical name as:

(E)-4-Hydroxy-N'-(naphthalen-2-ylmethylene)benzohydrazide²

That is not peptide nomenclature.

It is a benzohydrazide small-molecule scaffold.

There is:

no amino-acid sequence
no peptide length
and no peptide-bond-defined structure

So if a peptide vendor sells SLU-PP-332 alongside BPC-157, retatrutide, or CJC-1295, that is a catalog-positioning choice, not a chemistry fact.

The “SLU” in the name really does mean Saint Louis University

The name is not random.

The SLU prefix refers to Saint Louis University, where the compound was developed in the broader Thomas P. Burris research program before Burris later moved to the University of Florida.³⁴

That part is worth noting because SLU-PP-332 is not some anonymous gray-market invention. It comes out of a real academic nuclear-receptor drug-discovery effort.

The mechanism: ERR agonism, not estrogen receptor agonism

SLU-PP-332 is a pan-agonist of estrogen-related receptors:

ERRα
ERRβ
ERRγ³²

The reported EC50 values are:

98 nM for ERRα
230 nM for ERRβ
430 nM for ERRγ¹²

This is where a lot of low-quality content gets sloppy.

ERR does not mean the same thing as the classical estrogen receptor.

ERRs are orphan nuclear receptors involved in transcriptional control of:

mitochondrial biogenesis
oxidative phosphorylation
fatty-acid oxidation
and broader oxidative metabolism³⁵

That is why SLU-PP-332 gets called an exercise mimetic.

The idea is not that it literally makes tissue “exercise.”

The idea is that it activates some of the same gene-expression programs that endurance training activates, especially in metabolically active tissue.

Why the exercise-mimetic label caught on

The foundational ACS Chemical Biology paper from Billon et al. (2023) showed that SLU-PP-332 induced an ERRα-dependent acute aerobic exercise response and enhanced exercise capacity in mice.³

The findings were striking enough that the University of Florida’s news release highlighted the compound as an “exercise-mimicking drug,” summarizing that treated mice ran:

70% longer
and 45% farther than untreated mice⁶

That is not a trivial preclinical signal.

It is also probably the main reason the compound spread so quickly through the peptide gray market.

“Exercise mimetic” is simply a very marketable phrase.

The metabolic-syndrome paper is the one vendors lean on most

The Journal of Pharmacology and Experimental Therapeutics follow-up paper from Billon et al. (2024) is the other core SLU-PP-332 source.⁵

That study examined the compound in mouse models of obesity and metabolic syndrome and reported that SLU-PP-332:

increased energy expenditure
increased fatty-acid oxidation
reduced fat-mass accumulation
improved insulin sensitivity⁵

The University of Florida summary of that work added the key commercial talking points that now show up all over vendor pages:

obese mice lost 12% of body weight
over about 28 days
while eating the same amount of food
and without exercising more⁶

That is genuinely strong animal data.

But it is still animal data.

The biggest thing almost nobody explains well: the dosing gap

One of the more misleading parts of SLU-PP-332 marketing is how little attention gets paid to the actual mouse dosing used in the published work.

Supplier summaries and the 2024 JPET paper point back to rodent dosing around:

50 mg/kg
intraperitoneally
often twice daily in obesity experiments¹⁵

That creates a very large translation problem.

If you naively scale that directly by body weight, a 70 kg human equivalent lands in the gram-per-day range.

If you use the more defensible body-surface-area human-equivalent-dose approach, the number comes down a lot, but it is still roughly:

about 4 mg/kg/day human equivalent
or around 280 mg/day for a 70 kg adult

And because some of the mouse work used twice-daily dosing, people often round the practical implication to hundreds of milligrams per day, not the tiny milligram or microgram ranges frequently implied in gray-market conversation.

That does not tell you what a human dose should be.

It tells you something simpler:

there is a giant gap between the published animal protocols and the way many people casually talk about the compound online.

No human clinical trials means no validated human dosing

As of May 12, 2026, a search of ClinicalTrials.gov for SLU-PP-332 returns no registered studies.⁷

That means:

no registered Phase 1
no human pharmacokinetic profile
no human safety range
no human efficacy study
and no validated human dosing framework

This is not one of those cases where the compound is “understudied in humans.”

It is more accurate to say:

the clinical-development story has not started yet.

That point also fits the UF reporting, which noted that the Burris group still needed to optimize the scaffold further, especially toward more practical oral use, before it could plausibly move toward human studies.⁶

In fact, the later SLU-PP-915 paper reinforces that development path: the research group moved on to characterize an orally active ERR agonist because SLU-PP-332 itself lacked oral bioavailability.⁸

That is a very important clue about where the science actually is.

Why peptide vendors sell it anyway

This part is less mysterious than it sounds.

Peptide vendors increasingly sell a mixed catalog that includes:

peptides
peptide-adjacent biologics
small molecules
and other “research use only” compounds

SLU-PP-332 is a particularly clean example of that blur.

BioLongevity Labs uses the phrase “SLU-PP-332 Peptide” in a research article URL and sells a capsule product built around the compound.⁹

Simple Peptide sells SLU-PP-332 Capsules and describes it as an ERR agonist, even while the site’s branding clearly places it inside a peptide-vendor ecosystem.¹⁰

At the same time, Peptide Sciences is actually more chemically accurate than many of its peers here: its product page calls SLU-PP-332 a “low-molecular-weight synthetic small molecule” and later a “research-grade small molecule compound.”¹¹

That makes SLU-PP-332 a useful case study.

The market is telling you:

it is sold to peptide buyers
but it is not a peptide

Those are not the same thing.

What the evidence really supports

The strongest fair summary is:

Yes, SLU-PP-332 is a real academic research compound.
Yes, the mechanism is genuinely interesting.
Yes, the mouse endurance and metabolic data are strong enough to explain the hype.
No, it is not a peptide.
No, it has not entered registered human trials.
No, current online dosing confidence is not supported by human evidence.

That is the whole story in one place.

SLU-PP-332 is probably best understood as:

a high-interest preclinical ERR agonist that peptide vendors market aggressively because the mouse data are exciting and the category confusion helps demand.

That does not make the science fake.

It just means the marketing story is getting ahead of the actual development stage.