SLU-PP-332

SLU-PP-332 is a lab-made molecule sold and talked about in the “research chemical” market as an “exercise mimetic” — a compound meant to switch on some of the body’s responses to exercise without the workout. It often gets lumped in with peptides online, but it is not a peptide. It is a small molecule in the hydrazide chemical family (CAS 303760-60-3, a unique ID number for the compound) that turns on a set of cell receptors called the estrogen-related receptors (ERRα/β/γ). Everything we know about it comes from studies in mice and cells. There are no human trials and no human safety data, so any promises about endurance, fat loss, or living longer are guesses carried over from rodents.

What it is

SLU-PP-332 is a synthetic small molecule that activates (agonizes) three closely related cell receptors: ERRα, ERRβ, and ERRγ. Chemically it belongs to the hydrazide class of small molecules (CAS 303760-60-3), and to be clear, it is not a peptide — selling it as one is simply wrong. It works most strongly on ERRα. The concentration needed to get a half-strength effect (called the EC50) is roughly 98 nM for ERRα, 230 nM for ERRβ, and 430 nM for ERRγ, according to vendor and reference data (Tocris, AdipoGen). In plain terms: lower numbers mean it takes less of the compound to act, so it hits ERRα the easiest.

ERRα is a kind of master switch for how cells build and run their mitochondria (the tiny “power plants” inside cells), how they burn fuel, and how they break down fat. Flipping that switch turns on an “acute aerobic exercise” gene program in muscle — including a gene called DDIT4 — even though no actual exercise happened. That muscle effect is the real reason for the “exercise mimetic” nickname, and the nickname does match what the studies show. The chemistry started with a Ligand Pharmaceuticals patent (US 8,680,150), and the exercise-mimetic ERR-activating discovery was the work of the Burris and Elgendy labs. There is also a newer cousin compound that can be taken by mouth, SLU-PP-915, which is likewise still at the animal-study stage and was reported in 2025/2026.

The claims

In the consumer and research-chemical market, SLU-PP-332 gets promoted for endurance and stamina, fat loss, better metabolic health, and even a longer life — often pitched as “exercise in a pill.” All of these are stretched from mouse data. Not one of them is backed by a human result.

What the evidence actually shows

Humans: none. There is zero human evidence on whether it works or whether it’s safe — no registered clinical trial (no NCT number), and no human data on how the body handles it, what dose to use, or its safety, as of June 2026.

Animal and cell studies (real findings):

• Endurance and body composition (Billon et al., ACS Chem Biol 2023): In mice, short-term dosing increased running endurance, raised the share of type IIa “oxidative” muscle fibers (the kind built for stamina), boosted energy burned and fat burned, and lowered fat mass without the mice eating less. The endurance benefit depended on ERRα — block that receptor and the benefit went away.
• Metabolic syndrome (Billon et al., JPET 2024): In mice made obese by diet and in ob/ob mice (a strain genetically prone to obesity), SLU-PP-332 cut obesity and improved insulin sensitivity and other markers of metabolic syndrome.
• Mechanistic/cell work: Studies in cell lines (for example, C2C12 muscle cells) and in test-tube receptor experiments show more mitochondrial activity and the same acute-exercise gene program switching on.

About the “20–30% running improvement” figure people quote online: that number comes from the mouse studies above and from secondhand write-ups of them. Treat it as a rough, mouse-only estimate — it should never be passed off as exact or as something proven in people.

Bottom line on the evidence: the rodent data are genuinely interesting, consistent with each other, and point to a clear ERRα-based mechanism — but none of it proves any benefit, dose, or safety in people.

Legal and regulatory status

• Not approved anywhere. SLU-PP-332 is preclinical, research-grade material. It is not an approved drug, not a dietary supplement, and not a cosmetic. Chemical and “research chemical” vendors sell it as reference material that is not meant for human use.
• No human trials. No registered study (no NCT number) and no human data on how the body processes it, its safety, or whether it works has been found as of June 2026. The original labs are still actively refining the chemistry, and the orally active cousin SLU-PP-915 (reported 2025/2026) is also at the animal stage.
• Anti-doping (WADA): SLU-PP-332 is not listed by name on the WADA 2026 Prohibited List, and the official USADA materials do not name ERR agonists or SLU-PP-332. Secondhand sources claiming it is spelled out on the list are overstating things. As an endurance-boosting metabolic compound / exercise mimetic, it sits in the same general group WADA polices under S4 (Hormone and Metabolic Modulators) — and in the 2026 list, “Metabolic Modulators” is subsection S4.4 (which covers AMPK activators such as AICAR and MOTS-c, the new-for-2026 mitochondrial uncoupler BAM15, PPARδ agonists such as GW1516/cardarine, and Rev-erbα agonists such as SR9009/SR9011). Some older years of the list number this as S4.5. Because SLU-PP-332 isn’t named, no specific code should be claimed for it. The S0 category (a catch-all for “non-approved substances”) also likely applies, since it isn’t approved for human use. This is reasoned grouping on our part, not a confirmed listing.
• Detection is being prepared. A peer-reviewed doping-control method paper (Avliyakulov, Sobolevsky, Ahrens, Drug Test Anal 2026) mapped out 22 metabolites that SLU-PP-332 forms in human liver tissue in the lab, so urine tests can spot it. A separate companion paper (Möller et al., Thevis group, Rapid Commun Mass Spectrom 2026), covering both SLU-PP-332 and SLU-PP-915, openly flags their “doping potential.” Together these are a strong sign that anti-doping labs are gearing up to test for it. Athletes should assume it is banned in sport.

Safety

Human safety is unknown. There is no human data of any kind — nothing on toxicity, on how the body handles it, on the right dose, or on long-term use.

The theoretical worries — and none of them have been studied in people — include the following. ERRα and the mitochondrial pathways it controls show up all over the body, including in the heart, so unintended effects on the heart or metabolism are biologically plausible but untested. And constantly switching on a master metabolic regulator may have long-term consequences nobody has measured. On top of all that, grey-market “research chemical” material has no verified purity or identity, which is a real danger on its own, separate from the molecule itself.

The honest bottom line on safety: the evidence is thin and entirely from animals and cells, so any use in people is untested experimentation.

Bottom line

SLU-PP-332 is a synthetic small molecule that turns on the ERR receptors — not a peptide — with genuinely interesting, ERRα-driven “exercise mimetic” effects in mice, including better endurance and less fat without the animals eating less. But it is animal-stage only: there are no human trials, no human safety data, and no approved use anywhere. It is not yet named on the WADA list, though tests to detect it are already being published, and athletes should treat it as banned. Every human-facing claim about endurance, fat loss, or longevity is stretched from rodent studies, and using it in people is untested experimentation.

Evidence grade: 3/10 · Animal only.

Sources

• Billon C, Sitaula S, et al. Synthetic ERRα/β/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity. ACS Chem Biol. 2023. PMID 36988910.
• Billon C, Schoepke E, Avdagic A, et al. A Synthetic ERR Agonist Alleviates Metabolic Syndrome. J Pharmacol Exp Ther. 2024;388(2):232-240. PMID 37739806.
• Avliyakulov NK, Sobolevsky T, Ahrens E. Analysis and Identification of In Vitro Metabolites of Exercise Mimetic SLU-PP-332 ERRα/β/γ Agonist for Doping-Control Purposes. Drug Test Anal. 2026;18(3):439-450. PMID 41688415.
• Möller I, et al. In Vitro Metabolism and Analytical Characterization of SLU-PP-332 and SLU-PP-915: Novel Pan-ERR Agonists With Doping Potential. Rapid Commun Mass Spectrom. 2026.
• Billon C, Appourchaux K, Côté I, Burris TP. An orally active estrogen receptor–related receptor agonist, SLU-PP-915, enhances aerobic exercise capacity. J Pharmacol Exp Ther. 2026 (online Dec 2025). PMID 41421047.
• WADA — The Prohibited List
• USADA — What Should Athletes Know About GW1516?