SLU-PP-332 in the research literature: an ERR agonist, not a peptide, and how it is studied

SLU-PP-332 is one of the most searched compounds in the research-chemical market and one of the least understood. It is routinely listed next to peptides but is a small synthetic molecule, it was published only in 2023, and nearly everything known about it comes from a single academic group’s mouse and cell work. This guide explains what it is, what has actually been reported, what has not, and how a laboratory should handle it. For laboratory research use only.

What SLU-PP-332 is

SLU-PP-332 is a synthetic agonist of the oestrogen-related receptors (ERRs), a family of three orphan nuclear receptors, ERRα, ERRβ and ERRγ, that regulate genes involved in mitochondrial biogenesis, oxidative metabolism and fatty-acid oxidation. Despite the name, ERRs do not bind oestrogen; “oestrogen-related” refers to sequence similarity with the oestrogen receptor. The compound was developed in Thomas Burris’s laboratory at Saint Louis University (hence “SLU”) as an analogue in the same chemical series as the earlier ERRγ-selective agonist GSK4716, and was designed to activate all three ERR isoforms, with the strongest reported activity at ERRα.

Compound class	Small molecule; pan-ERR (α/β/γ) agonist — not a peptide
Also known as	SLU-PP-332, SLU PP 332, SR9861 (alternate code)
CAS number	303760-60-3
Molecular formula / weight	C18H14N2O2 · ≈ 290.3 g/mol
Primary target	ERRα (also ERRβ, ERRγ)
Solubility	DMSO; poorly water-soluble (typical of this chemical class)
First publication	Billon et al., ACS Chemical Biology, 2023

What the literature has studied

Muscle gene expression and exercise capacity in mice

The founding paper (Billon et al., 2023) reported that SLU-PP-332 activated ERRα-dependent transcription in cultured muscle cells and, in mice, increased the expression of genes associated with the acute response to aerobic exercise, mitochondrial function and fatty-acid oxidation in skeletal muscle. Treated mice showed an increased proportion of oxidative (type IIa) muscle fibres and ran further and longer in treadmill endurance tests than vehicle-treated controls. The authors used the phrase “exercise mimetic” to describe this pattern of gene expression, and the term has followed the compound ever since.

Diet-induced obesity models

A follow-up from the same group (Billon et al., Journal of Pharmacology and Experimental Therapeutics, 2024) reported that in mice fed a high-fat diet, SLU-PP-332 reduced weight gain and fat-mass accumulation relative to controls, with increased energy expenditure and fatty-acid oxidation and without a reduction in food intake. The same paper reported improved glucose tolerance in the treated animals.

Mechanism

The proposed mechanism is direct binding to and activation of ERRα, which, with its co-activator PGC-1α, drives the mitochondrial and oxidative-metabolism gene programme that exercise normally induces. ERRα-knockout experiments in the 2023 paper were used to show the effect depends on ERRα. Work on related ERR agonists has also examined cardiac and kidney models, but those studies used other compounds in the series rather than SLU-PP-332 itself.

Human data

There are none. SLU-PP-332 has not been tested in people. The intellectual property has been licensed to a biotechnology company developing next-generation ERR agonists for clinical use, which is a different programme from the research compound sold today.

What the literature has not shown

The entire evidence base is two to three papers from one laboratory, in mice and cell lines, published since 2023. Independent replication is still limited. Reported effects on endurance and body composition are mouse findings at specific doses and routes and say nothing about effects in humans. Pharmacokinetics, long-term safety and off-target activity in any species are largely uncharacterised. Any supplier describing this compound in terms of human performance or weight is describing something the literature does not contain.

Why it is listed with peptides

SLU-PP-332 appears in research-peptide catalogues because the same laboratories that study peptides in metabolic and muscle models also study it, not because of any chemical similarity. It is a 290 Da aromatic small molecule; the peptides it sits next to are 1,000–5,000 Da chains of amino acids. The practical differences matter: it is not lyophilised from water, it is not reconstituted with bacteriostatic water, and its certificate of analysis will show a single HPLC peak and a mass-spectrometry match rather than a peptide sequence or net-peptide-content figure.

How SLU-PP-332 is supplied for research

Quantum Peptides supplies SLU-PP-332, 1 mg capsules, each lot tested by an independent US laboratory for identity (mass spectrometry) and purity (HPLC), with the certificate linked on the product page. For a research compound of this class, the certificate should show the expected mass (≈290) and a purity figure by HPLC; our guide to reading a certificate of analysis explains the fields, most of which apply equally to small molecules.

Handling and storage

Store at room temperature or below, dry and protected from light, in the original sealed container. For in-vitro work the compound is normally dissolved in DMSO to make a concentrated stock, then diluted into assay medium; keep the final DMSO concentration low enough for the cell line (typically ≤0.1%). Aqueous solubility is poor, so do not expect it to dissolve in water or buffer alone. Prepare DMSO stocks in small single-use portions and store them frozen at −20 °C to limit freeze–thaw cycles.

Frequently asked questions

Is SLU-PP-332 a peptide?

No. It is a synthetic small molecule (≈290 g/mol) that activates the oestrogen-related receptors. It is sold alongside peptides because the same research fields use it.

What does “ERR agonist” mean?

It binds and activates the oestrogen-related receptors, ERRα, ERRβ and ERRγ, nuclear receptors that switch on genes for mitochondrial biogenesis and oxidative metabolism. Despite the name, these receptors do not bind oestrogen.

What is the CAS number of SLU-PP-332?

303760-60-3.

Why is it called an “exercise mimetic”?

Because in the 2023 mouse study it induced a pattern of muscle gene expression similar to the acute response to aerobic exercise. The term describes a transcriptional signature in mice, not a demonstrated effect in people.

Has it been tested in humans?

No. All published data are from mice and cell lines.

Can I buy SLU-PP-332 for human use?

No. Quantum Peptides products are supplied for in-vitro and preclinical laboratory research only, not for human or veterinary use.

References

1. Billon C, Sitaula S, Banerjee S, et al. Synthetic ERRα/β/γ agonist induces an ERRα-dependent acute aerobic exercise response and enhances exercise capacity. ACS Chemical Biology. 2023.
2. Billon C, Schoepke E, Avdagic A, et al. A synthetic ERR agonist alleviates metabolic syndrome. Journal of Pharmacology and Experimental Therapeutics. 2024.
3. Audet-Walsh É, Giguère V. The multiple universes of estrogen-related receptor α and γ in metabolic control and related diseases. Acta Pharmacologica Sinica. 2015.

Quantum Peptides supplies research compounds for in-vitro and preclinical laboratory research only. Products are not for human or veterinary use. This guide summarises published literature and is not guidance on administration of any kind.