SLU-PP-332 Research Compound

SLU-PP-332 is a synthetic small molecule that activates all three oestrogen-related receptors, ERR-alpha, ERR-beta and ERR-gamma, with its highest potency at ERR-alpha. It was described in 2023 by researchers working with Saint Louis University and is used in laboratory research on mitochondrial function, muscle fibre type and energy metabolism in cells and rodent models.

They are three nuclear receptors, proteins that sit on DNA and switch sets of genes on or off. They were named for their resemblance to the oestrogen receptors, but they do not bind oestrogen. ERR-alpha and ERR-gamma are especially abundant in tissues with high energy demands, such as heart, skeletal muscle and kidney, where they control genes for mitochondria and fat burning.

No. Despite the similar names, the oestrogen-related receptors are a separate family. In the 2023 study, SLU-PP-332 did not change the activity of oestrogen receptor alpha or beta, or of the other nuclear receptors tested, in cell-based assays. Its activity was confined to the three ERRs.

The ERRs are switched on by default: they are active without any ligand, and partner proteins such as PGC-1-alpha turn their activity up further. An agonist like SLU-PP-332 binds a pocket in the receptor and increases that activity beyond its normal level. Designing such compounds for ERR-alpha proved especially difficult, which is why SLU-PP-332 attracted attention.

It grew out of GSK4716, a compound reported by GlaxoSmithKline in 2005 that activated ERR-beta and ERR-gamma but not ERR-alpha. The Saint Louis group used the crystal structure of GSK4716 bound to ERR-gamma to redesign it, gaining about 50-fold in ERR-alpha potency. Both share the same acyl hydrazone core linking a phenol to an aromatic ring.

In full-length receptor assays its half-maximal concentrations were 98 nanomolar at ERR-alpha, 230 at ERR-beta and 430 at ERR-gamma, so it is about 2.3 times more potent at ERR-alpha than ERR-beta and 4.4 times more than ERR-gamma. It is therefore described as a pan-ERR agonist with a preference for ERR-alpha, rather than a selective one.

Older exercise mimetic work, such as studies of AICAR, targets AMPK, an enzyme that senses the cell’s energy level and acts within minutes by adding phosphate groups to other proteins. SLU-PP-332 instead acts on transcription factors, changing which genes are switched on, so its effects are studied through gene expression, mitochondrial content and fibre type over days to weeks.

In treated mice, muscle contained more mitochondria and mitochondrial DNA and more oxidative type IIa fibres. Sedentary mice ran about 70% longer and 45% further on a treadmill test than controls, and muscle gene expression overlapped with the pattern seen after a single bout of aerobic exercise, which is why the authors called it an exercise mimetic.

The researchers used mice in which ERR-alpha had been removed from skeletal muscle only. In normal littermates, SLU-PP-332 increased treadmill endurance and switched on genes such as Ddit4, Per1 and Alas2. In the knockout mice neither change occurred, which showed that ERR-alpha in muscle was needed for those particular effects.

Published mouse studies cover diet-induced and genetic obesity, where it raised energy expenditure and lowered fat mass; pressure-overload heart failure, where ERR-gamma was the main receptor involved; and the ageing kidney, where eight weeks in 21-month-old mice reversed several age-related changes. All of these are rodent findings from the same research network.

Yes, in culture. A 2025 pilot study grew muscle precursor cells from biopsies taken from less active women during hip surgery and treated them with SLU-PP-332, which raised PGC-1-alpha, ERR-alpha and SIRT1 and encouraged myotube formation. There are no published clinical trials of SLU-PP-332 in people.

SLU-PP-332 is not a controlled drug under the Misuse of Drugs Act 1971, including the Class C group covering anabolic steroids and growth hormones, and it is not a licensed medicine in the UK. It is sold in the UK as a research compound for laboratory use only, which is how Crown Peptides supplies it. This is general information, not legal advice.

SLU-PP-332 is coming soon to Crown Peptides in 5mg and 10mg vials, available singly or in packs of 3, 5 or 10 with a saving on every vial. Orders ship from the UK, and every batch is independently tested, with its Certificate of Analysis published on this page once stock arrives.

SLU-PP-332 weighs about 290 daltons, so a 5mg vial is roughly 17 micromoles and a 10mg vial roughly 34. Published cell work used it at 10 micromolar, so 5mg makes about 1.7 litres of medium at that concentration and 10mg about 3.4 litres. Its potency at ERR-alpha is around 98 nanomolar, so reporter assays use far less.

Keep the unreconstituted powder at -20°C ± 5°C, dry and away from light. The acyl hydrazone link at the centre of the molecule can slowly break down in water, so it is best kept dry, and published studies dissolved it in DMSO. Prepared solutions should follow storage conditions validated for your study design, and each batch’s Certificate of Analysis documents the material as dispatched.