SLU-PP-332: What the Mouse Studies Show, the Dose Math, and Why No Human Dose Exists

The short answer

SLU-PP-332 is a small molecule, not a peptide, that activates the estrogen-related receptors. In mice, 50 mg/kg twice a day by injection made them run about 70% longer. No human has taken it in a trial, so there is no human dose, and its developers report it is not absorbed by mouth.

By the Peptide Bureau editorial desk Category: Compound Reviews Published 8 November 2026 Read time: 7 minutes

SLU-PP-332 is sold next to peptides, but it is not one. It is a small synthetic molecule that switches on the estrogen-related receptors (ERR alpha, beta and gamma), the proteins that drive the muscle changes endurance training produces. In mice it made muscles more oxidative and let them run further. It has never been given to a person in a trial, and the lab that made it reports it is not absorbed when swallowed. What follows is what the papers show, the mouse doses, and what they convert to.

What SLU-PP-332 is

The compound came out of the Burris lab, then at Saint Louis University (hence SLU), and was described in 2023 as a pan-ERR agonist: it activates all three ERRs, most potently ERR alpha (Billon 2023, ACS Chem Biol). ERRs are nuclear receptors, switches inside the cell that turn on genes for mitochondria, fat burning and oxidative muscle fibres. Exercise turns them on; SLU-PP-332 was designed to do it without the exercise, which is why it gets called an exercise mimetic or "exercise in a pill".

Two things follow from it being a small molecule. It is not reconstituted like a peptide by default, and the "peptide" label sellers put on it is a shop category, not chemistry. Several of the authors hold stock in companies developing ERR agonists (Myonid Therapeutics, Pelagos Pharmaceuticals), which the papers declare.

What the research shows

Endurance in mice. After 7 days of 50 mg/kg twice a day by injection, treated mice ran about 70% longer and 45% further on a treadmill than untreated mice, with more type IIa oxidative fibres in the muscle (Billon 2023).
Obesity in mice. In diet-induced obese and ob/ob mice it raised energy expenditure and fat burning, reduced fat mass and improved insulin sensitivity (Billon 2024, J Pharmacol Exp Ther). The abstract gives no percentages, so we give none.
Heart failure in mice. At 25 mg/kg twice a day for 6 weeks it improved ejection fraction, reduced fibrosis and improved survival after pressure overload (Xu 2024, Circulation).
Ageing kidney in mice. Eight weeks of a pan-ERR agonist reversed age-related protein in the urine, podocyte loss and mitochondrial dysfunction in old mice (Wang 2023, Am J Pathol).
Human cells, not humans. A 2025 pilot study added it to muscle cells in a dish, alongside biopsies from 20 women having hip replacement surgery; the treated cells made more myotubes and less oxidative stress (Bonanni 2025, Front Physiol). Nobody took it.

ClinicalTrials.gov lists no trial of SLU-PP-332 (searched 7 November 2026). Every result above is in mice or in a dish.

SLU-PP-332 dosage chart: the mouse doses and what they convert to

There is no human dose, because no human has been dosed in a study. The table converts the mouse doses with the body-surface-area factor in FDA's 2005 guidance (divide a mouse mg/kg dose by 12.3; FDA guidance, Table 1) for a 70 kg adult, rounded to the nearest 10 mg. Read the last column as arithmetic, not as a dose.

Study	Animals	Dose and route	Mouse dose a day	Converted, 70 kg adult, a day
Billon 2023, exercise study	Healthy mice	50 mg/kg twice a day, injected into the abdomen (IP), 7 to 15 days	100 mg/kg	about 570 mg
Xu 2024, heart failure study	Mice with pressure-overload heart failure	25 mg/kg twice a day, IP, 6 weeks	50 mg/kg	about 280 mg

Why the right-hand column overstates what a capsule does: every mouse result came from injections into the abdomen, and the lab that developed SLU-PP-332 reports that it "lacks oral bioavailability", which is why it built an oral successor, SLU-PP-915 (Billon 2026, J Pharmacol Exp Ther). The FDA conversion was written to pick a safe first dose for a trial from animal toxicity data, not to predict an effective one. Tablet and capsule strengths printed by sellers are the sellers' numbers.

Oral SLU-PP-332: the absorption problem

Most SLU-PP-332 sold online is a capsule or tablet. The developers' own 2026 paper describes SLU-PP-332 as lacking oral bioavailability and presents SLU-PP-915 as the orally active compound, effective by mouth once adjusted for blood levels (Billon 2026). No published study has measured what a swallowed SLU-PP-332 capsule delivers to muscle in a person. Anyone reporting results from capsules is reporting something the chemistry gives little reason to expect.

Safety and what is not known

The mouse papers report no overt toxicity at 50 mg/kg twice a day for 10 days, with normal blood counts and electrolytes (Billon 2023), and none at 25 mg/kg twice a day over 6 weeks (Xu 2024). That is short exposure in one species. There are no human safety data at all, no data on long-term use, and nothing on how it interacts with medicines. ERRs act in the heart, liver, kidney and fat as well as muscle, so an effect in one tissue is an effect in many.

SLU-PP-332 and drug testing

The World Anti-Doping Agency prohibits exercise mimetics and metabolic modulators, and two anti-doping laboratories published methods in 2026 to find SLU-PP-332 and its breakdown products in samples (Avliyakulov 2026, Drug Test Anal; Möller 2026, Rapid Commun Mass Spectrom, from the Cologne laboratory). A tested athlete should assume it will be looked for.

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Frequently asked questions

Is SLU-PP-332 a peptide?

No. It is a small synthetic molecule that activates the estrogen-related receptors (ERR alpha, beta and gamma). Sellers list it with peptides, but that is a shop category; it has no amino acid chain.

What is the SLU-PP-332 dosage?

There is no human dosage, because no human trial has been run. Mice in the exercise study received 50 mg/kg twice a day by injection into the abdomen, and in the heart failure study 25 mg/kg twice a day. FDA body-surface arithmetic turns those into roughly 570 and 280 mg a day for a 70 kg adult, which is arithmetic, not a dose.

Does oral SLU-PP-332 work?

There is no study of oral SLU-PP-332 in people. The lab that developed it reports in a 2026 paper that SLU-PP-332 lacks oral bioavailability, and it built a separate compound, SLU-PP-915, to work by mouth.

What did SLU-PP-332 do in mice?

After 7 days at 50 mg/kg twice a day, mice ran about 70% longer and 45% further than untreated mice, with more oxidative type IIa muscle fibres. In obese mice it raised energy expenditure, reduced fat mass and improved insulin sensitivity, and in mice with heart failure it improved heart function and survival.

Is SLU-PP-332 banned in sport?

The World Anti-Doping Agency prohibits exercise mimetics and metabolic modulators, and anti-doping laboratories published detection methods for SLU-PP-332 in 2026. A tested athlete should assume it is screened for.

Is SLU-PP-332 safe?

Nobody knows for people. Mouse studies found no overt toxicity over 10 days at 50 mg/kg twice a day and over 6 weeks at 25 mg/kg twice a day. There are no human safety data, no long-term data and no data on interactions with medicines.

Sources (checked 7 November 2026)

Billon C et al. Synthetic ERRα/β/γ agonist induces an ERRα-dependent acute aerobic exercise response and enhances exercise capacity. ACS Chem Biol 2023;18(4):756-771 (doses, endurance, toxicity; full text PMC11584170). Checked 7 November 2026.
Billon C et al. A synthetic ERR agonist alleviates metabolic syndrome. J Pharmacol Exp Ther 2024;388(2):232-240. Checked 7 November 2026.
Xu W, Billon C et al. Novel pan-ERR agonists ameliorate heart failure through enhancing cardiac fatty acid metabolism and mitochondrial function. Circulation 2024;149(3):227-250 (25 mg/kg twice daily; full text PMC10842599). Checked 7 November 2026.
Wang XX et al. Estrogen-related receptor agonism reverses mitochondrial dysfunction and inflammation in the aging kidney. Am J Pathol 2023. Checked 7 November 2026.
Bonanni R et al. Targeting ERRs to counteract age-related muscle atrophy associated with physical inactivity: a pilot study. Front Physiol 2025. Checked 7 November 2026.
Billon C et al. An orally active estrogen receptor-related receptor agonist, SLU-PP-915, enhances aerobic exercise capacity. J Pharmacol Exp Ther 2026;393(1):103787 (SLU-PP-332 lacks oral bioavailability). Checked 7 November 2026.
Avliyakulov NK et al. In vitro metabolites of exercise mimetic SLU-PP-332 for doping-control purposes. Drug Test Anal 2026;18(3):439-450. Checked 7 November 2026.
Möller T, Krug O, Thevis M. In vitro metabolism and analytical characterization of SLU-PP-332 and SLU-PP-915. Rapid Commun Mass Spectrom 2026;40(8):e70039. Checked 7 November 2026.
FDA. Estimating the maximum safe starting dose in initial clinical trials for therapeutics in adult healthy volunteers, 2005 (Table 1, mouse factor 12.3). Checked 7 November 2026.
ClinicalTrials.gov search for SLU-PP-332 (no registered trials). Checked 7 November 2026.

SLU-PP-332 is a research chemical with no human trial; every figure here is from mouse or cell studies. Labels and trial records change; the leaflet in your box and your prescriber come first. Educational content, not medical advice.