SLU-PP-332
Also known as: SLU PP 332, Pan-ERR agonist SLU-PP-332, Exercise mimetic (ERR agonist)
Lower numbers = closer to natural. Higher numbers = more enhanced.
Why this rating?
SLU-PP-332 is a synthetic pan-ERR (estrogen-related receptor) agonist marketed as an "exercise mimetic", in mice it up-regulates mitochondrial biogenesis, fat oxidation (~25% increase vs vehicle), energy expenditure and endurance without training. It is metabolic/endurance-oriented, not anabolic, and would enhance conditioning beyond what the same training alone produces, mechanistically in the same family as Cardarine and Stenabolic, but rated below both here because it has zero human data of any kind (even its 2025 oral successor, SLU-PP-915, has only been tested in mice). Rated 4 with a heavy caveat: this rating reflects the animal data only. There are NO human trials, so real-world potency and safety in people are genuinely unknown, and the rating could move in either direction as human data appears (if it ever does).
Overview
An experimental synthetic agonist of the estrogen-related receptors (ERRalpha/beta/gamma), a family of orphan nuclear receptors that govern mitochondrial biogenesis and oxidative metabolism. Nicknamed an "exercise mimetic" because in rodents it reproduces some of the metabolic adaptations of endurance training (more mitochondria, greater fat oxidation and improved endurance) without exercise. It is an early-stage research compound: essentially all data is from mice, and honest evaluation means treating human benefit and safety as unproven.
Important Warnings
- •NO human trials exist - all benefit claims are extrapolated from mice
- •No established human dose and no human safety data
- •ERRalpha is linked to breast and ovarian cancer (and possibly others) - a real theoretical concern with chronic agonism
- •Poor oral bioavailability - oral "SLU-PP-332" capsules may deliver little to no systemic exposure (a purpose-built oral successor, SLU-PP-915, exists for this reason)
- •Unregulated research chemical - purity and identity vary by source
- •Marketed misleadingly as a "peptide" or finished supplement; it is neither
Purpose & Use Cases
Endurance / Mitochondrial Biogenesis (preclinical)
In mice, increases oxidative muscle fibers and running endurance by activating the same mitochondrial-biogenesis program as endurance training.
Fat Oxidation / Body Composition (preclinical)
Raised energy expenditure and fatty-acid oxidation and blunted fat-mass gain on a high-fat diet in rodents, without reducing food intake.
Metabolic Health (research interest)
Studied as a candidate for obesity, metabolic syndrome and age-related mitochondrial decline, as a research tool, not an approved therapy.
Benefits
- Activates mitochondrial biogenesis and fat oxidation (exercise-mimetic pathway) - in animals
- Improved endurance and oxidative fiber type in rodents
- Reduced fat-mass gain without appetite suppression (rodents)
- Does not act on hormones or the HPTA
- Mechanistically novel and of genuine scientific interest
Good to Know
No human data - this is the headline
Every benefit attributed to SLU-PP-332 comes from mice. There are no human trials of any size. Effective dose, real-world potency, tolerability and long-term safety in people are all genuinely unknown. Treat glowing vendor claims accordingly.
"Estrogen-related receptor" does NOT mean estrogen
ERRs are orphan nuclear receptors named for structural similarity to the estrogen receptor - they do not bind estrogen and do not signal like it. SLU-PP-332 has no estrogenic activity, does not aromatize, and has no PCT relevance. The name confuses a lot of people.
Not a peptide and not anabolic
It is a small-molecule nuclear-receptor agonist, not a peptide, and it targets mitochondrial/oxidative metabolism and endurance - not muscle protein synthesis. It will not build muscle or replace training for hypertrophy.
Poor pharmacokinetics
In rodents it had short exposure and needed twice-daily injection; oral bioavailability is poor, which is why it is sold as an injectable. This makes any consumer "dose" guesswork.
A real (theoretical) cancer question
ERRalpha (ESRRA) is well documented as over-expressed in breast and ovarian cancer, where it is linked to metastasis and worse prognosis; evidence in other cancer types is less established. Chronically switching ERR signaling ON with a pan-agonist is a legitimate theoretical concern that no one has evaluated in humans - a reason for genuine caution, not hype.
A newer oral cousin exists: SLU-PP-915
In 2025-2026 the same lab (Burris et al., Saint Louis University) published SLU-PP-915, a chemically distinct pan-ERR agonist purpose-built to fix SLU-PP-332's poor oral bioavailability, reporting comparable exercise-mimetic effects in mice when dosed orally. It is even newer and, like SLU-PP-332, has no human data - but its existence confirms that oral SLU-PP-332 products face a real absorption problem.
Dosage Guidelines
| Experience Level | Dosage Range |
|---|---|
| Beginner | 500 – 500 mcg/day |
| Intermediate | 500 – 1000 mcg/day |
| Advanced | 1000 – 1500 mcg/day |
There is NO clinically validated human dose. Every published efficacy figure is preclinical. Mouse studies used ~50 mg/kg intraperitoneally twice daily for up to 28 days (with plasma/muscle exposure measured only hours after each injection), which cannot be reliably scaled to a human dose. The 500 mcg-1.5 mg/day SC range above reflects informal community/vendor dosing consensus built by scaling the mouse data down, NOT a clinical protocol. Treat it as an uncertain, unverified starting point at best. Poor oral bioavailability is why researchers injected it and why it is typically sold as an SC vial by grey-market vendors; a chemically distinct successor, SLU-PP-915, was purpose-built to be orally active and reported comparable exercise-mimetic effects in mice (Billon et al., J Pharmacol Exp Ther, 2025/2026). Oral SLU-PP-332 capsules sold commercially may deliver minimal or unpredictable systemic exposure. Any human use is uncharted experimentation: no safety data, no confirmed effective dose, and no long-term human information exist.
Short in preclinical work (twice-daily dosing needed in mice); not characterized in humans.
Side Effects
Unknown Human Safety Profile
commonThe single most important "side effect" is that there is essentially no human safety data. Nothing about tolerability, long-term effects, or dose-response in people has been established. Treat all human use as experimental.
Recognize the evidence gap. There is no way to reliably predict or mitigate effects without human data.
Theoretical Cancer / Proliferation Concern
rareERRalpha (ESRRA) is well documented as over-expressed in breast and ovarian cancer, where it correlates with worse prognosis and drives metastatic signaling; its role in other tumor types is less firmly established. Chronically agonizing ERR signaling with a pan-agonist raises a theoretical proliferation concern that has not been evaluated in humans.
Unquantified. A reason for real caution with sustained use given the lack of long-term data.
Sourcing / Purity Risk
commonAs an unregulated research chemical, purity, identity and dosing accuracy vary widely by source.
Third-party testing / certificate of analysis if used at all.
General Mitigation Strategies
Honest bottom line: SLU-PP-332 has never been tested in humans, so its side-effect profile in people is unknown. The compelling rodent data does not establish safety, an effective dose, or long-term outcomes. The theoretical ERRalpha/cancer link and the total absence of human data are the main reasons for caution. This is early-stage research material, not a validated supplement or drug.
Post Cycle Therapy (PCT)
Not hormonal in the androgen sense and does not act on the HPTA. No PCT required. (Despite "estrogen-related receptor" in the name, ERRs are orphan nuclear receptors and do NOT bind estrogen or signal like the estrogen receptor.)
How It Works
SLU-PP-332 directly agonizes the ERR family of nuclear receptors (with slightly greater potency at ERRalpha). ERRs are master regulators of the genes controlling mitochondrial biogenesis, oxidative phosphorylation and fatty-acid oxidation, the same programs that endurance exercise activates via PGC-1alpha/ERR signaling. By switching this program on pharmacologically, in mice the compound raised resting energy expenditure, increased fatty-acid oxidation (~25% vs vehicle), expanded type IIa oxidative muscle fibers, improved running endurance and reduced fat-mass gain on a high-fat diet, all without changing food intake. Whether any of this translates to humans is untested.
Fundamentals
Reference on the practices relevant to SLU-PP-332: how they are done and where they go wrong. Not a recommendation to use it.
Legal Status
Not approved for human use anywhere. No human clinical trials.
Legal status varies by country and changes over time. This is a general summary, not legal advice.
WADA Status
With no approval for human use anywhere, SLU-PP-332 falls under S0 (any pharmacological substance not addressed by other sections and with no current approval for human therapeutic use is prohibited at all times). As a metabolic/exercise-mimetic agent it could also be captured under S4.4.1 (Metabolic Modulators, the same subsection covering Cardarine/GW-501516 and Stenabolic/SR9009). It is not yet named individually on the WADA list, so this classification is inferred rather than explicit. Analytical detection methods (including metabolite profiling) are already being published in anti-doping literature.
References
- PMC - A Synthetic ERR Agonist Alleviates Metabolic Syndrome (mouse data)
- bioRxiv - A Synthetic ERRalpha Agonist Induces an Acute Aerobic Exercise Response and Enhances Exercise Capacity
- PMC - In Vitro Metabolism of SLU-PP-332/SLU-PP-915: Pan-ERR agonists with doping potential
- PubMed - Billon et al., An Orally Active ERR Agonist, SLU-PP-915, Enhances Aerobic Exercise Capacity (J Pharmacol Exp Ther, 2025/2026)