Last Updated: April 14, 2026
SLU-PP-332 is a research chemical and synthetic agonist of the estrogen-related receptor (ERR) family — specifically ERR-alpha, ERR-beta, and ERR-gamma. Important clarification up front: SLU-PP-332 is not a peptide. It is a small-molecule orphan nuclear receptor agonist, despite often being discussed alongside peptide research compounds in the “exercise mimetic” research category. It was developed by researchers at Saint Louis University (hence the “SLU” prefix) and has drawn substantial research interest because preclinical data suggest it activates many of the same downstream transcriptional programs induced by endurance exercise, including mitochondrial biogenesis, oxidative-fiber-type muscle adaptation, and enhanced fatty acid oxidation. Published studies suggest SLU-PP-332 increases running capacity in rodent models and reduces body fat accumulation on high-fat diets without requiring physical activity. Preclinical research indicates these effects are mediated through direct ERR pan-agonism, which upregulates mitochondrial and oxidative-metabolism gene networks. This guide summarizes the current SLU-PP-332 research literature, the biology of ERR signaling, and standard reconstitution and storage practices for laboratory research.
Quick Facts
- Compound class: Small-molecule nuclear receptor agonist (NOT a peptide)
- Target: Estrogen-related receptors ERR-alpha, ERR-beta, ERR-gamma (pan-ERR agonist)
- Approximate molecular weight: approximately 471 Da
- Originating group: Saint Louis University medicinal chemistry research
- Primary mechanism: ERR transcriptional agonism; upregulation of oxidative metabolism genes
- Research format: Lyophilized powder or solid, 5 mg typical research pack
- Solubility: Poorly water-soluble; DMSO commonly used as research stock solvent
- Storage (solid): -20 degrees C, sealed, desiccated, protected from light
- Storage (DMSO stock): -80 degrees C preferred; minimize freeze-thaw cycles
What is SLU-PP-332 and why is it described as an “exercise in a bottle” research compound?
SLU-PP-332 is a small-molecule agonist of the estrogen-related receptor (ERR) family of orphan nuclear receptors. It was synthesized and characterized by the Burris laboratory at Saint Louis University and has become one of the most-discussed research compounds in the “exercise mimetic” category. The “exercise in a bottle” phrasing, while catchy and widely repeated in research reporting, is a simplification. Published studies suggest SLU-PP-332 recapitulates important transcriptional signatures of endurance exercise — particularly mitochondrial biogenesis, oxidative muscle-fiber remodeling, and enhanced fatty acid utilization — but it does not reproduce the cardiovascular, musculoskeletal, and neurological benefits of actual physical activity. Preclinical research indicates the compound is a useful tool for dissecting ERR-driven metabolic programs in the laboratory, not a replacement for exercise. Investigators should think of SLU-PP-332 as a targeted research probe of ERR biology that produces exercise-overlapping gene expression in controlled rodent and cell-culture models.
Is SLU-PP-332 a peptide? (A direct answer)
No — SLU-PP-332 is not a peptide. This is an important distinction because many research compounds discussed in longevity and metabolic research contexts are peptides (MOTS-c, Epithalon, BPC-157, GHK-Cu), and SLU-PP-332 is often grouped with them in informal research discussion because of its “exercise mimetic” framing. Chemically, SLU-PP-332 is a small organic molecule with a molecular weight around 471 Da, developed through medicinal chemistry optimization of ERR-binding scaffolds. Peptides, by contrast, are chains of amino acids connected by peptide bonds and are typically biosynthesized or solid-phase-synthesized. Published research on SLU-PP-332 describes it as a synthetic ERR agonist or nuclear receptor ligand, never as a peptide. This distinction matters for reconstitution — SLU-PP-332 is generally poorly water-soluble and typically requires DMSO as a stock solvent, whereas peptides typically reconstitute in bacteriostatic or sterile water. Researchers should verify solubility guidance from supplier documentation for any specific batch.
What are estrogen-related receptors (ERRs) and why do they matter in metabolic research?
The estrogen-related receptors are a three-member family of orphan nuclear receptors — ERR-alpha (NR3B1), ERR-beta (NR3B2), and ERR-gamma (NR3B3) — named for their sequence similarity to the classical estrogen receptors, despite the fact that they do not bind estradiol and are not activated by estrogen. ERRs are constitutive transcriptional regulators that partner with PGC-1-alpha and PGC-1-beta coactivators to drive programs of mitochondrial biogenesis, oxidative phosphorylation, fatty acid oxidation, and substrate handling. Published studies suggest ERR-alpha is particularly important in high-demand oxidative tissues such as skeletal muscle, heart, brown adipose, and kidney. Preclinical research indicates ERR activation directly upregulates hundreds of nuclear- and mitochondrial-encoded metabolic genes. Because PGC-1-alpha itself is induced by exercise, cold, and caloric restriction — all interventions that increase mitochondrial capacity — pharmacologically activating ERR downstream is an attractive research strategy for studying oxidative metabolism without the coactivator-induction bottleneck.
What does the published research say about SLU-PP-332 and exercise-related adaptations?
The core SLU-PP-332 research literature, including studies from the Burris group and independent follow-on work, reports several reproducible preclinical findings in rodent models. Published studies suggest SLU-PP-332 administration increases treadmill running capacity and time-to-exhaustion in mice, even without any training stimulus. Preclinical research indicates the compound promotes a shift toward Type I oxidative (slow-twitch) skeletal muscle fibers, increases mitochondrial content and citrate synthase activity, and upregulates fatty-acid-oxidation genes including CPT1B and MCAD. On the metabolic side, published studies suggest SLU-PP-332 reduces fat mass gain in high-fat-fed mice, improves glucose handling, and enhances whole-body energy expenditure. These findings are consistent with pan-ERR agonism activating the PGC-1-alpha / ERR oxidative axis. Investigators should note these are preclinical research results in rodent models and have not been translated to human clinical contexts.
How does SLU-PP-332 drive mitochondrial biogenesis in research models?
Mitochondrial biogenesis is the coordinated expansion of mitochondrial mass and function, requiring transcription of both nuclear-encoded and mitochondrial-encoded genes. PGC-1-alpha is the master coactivator of this program, but PGC-1-alpha requires partner transcription factors — including ERRs, NRF1, NRF2, and TFAM — to drive gene expression. By directly agonizing the ERR arm of this network, SLU-PP-332 effectively amplifies the transcriptional output of whatever PGC-1-alpha is present, increasing mitochondrial biogenesis gene expression even under baseline conditions. Published studies suggest this leads to increased mitochondrial DNA content, elevated electron-transport-chain subunit expression, and expanded oxidative capacity in skeletal muscle and other tissues. Preclinical research indicates these changes occur within days to weeks of SLU-PP-332 exposure in rodent models, paralleling but not replacing the adaptations produced by actual endurance training. This mechanism makes SLU-PP-332 a useful pharmacological tool for isolating ERR-dependent contributions to exercise adaptation in research.
Why are muscle fiber type switching and fatty acid oxidation relevant to SLU-PP-332 research?
Skeletal muscle fibers are broadly classified as Type I (slow-twitch, oxidative, fatigue-resistant) and Type II (fast-twitch, glycolytic, more fatigable). Endurance training shifts fiber composition toward Type I and increases the oxidative capacity of existing fibers. ERR-alpha and its PGC-1-alpha coactivator partner are central to this fiber-type program. Published studies suggest SLU-PP-332 administration in mice increases markers of oxidative, Type I-like fiber identity and elevates fatty acid oxidation capacity, two adaptations normally requiring weeks of training. Preclinical research indicates this is accompanied by upregulated expression of fatty-acid-transport and beta-oxidation genes (e.g., CD36, CPT1B, HADHA), along with increased myoglobin expression and oxidative enzyme activity. Because metabolically flexible, fatty-acid-oxidizing oxidative muscle is associated with favorable metabolic profiles in rodent models, SLU-PP-332 offers researchers a pharmacological route to study the fiber-type / fatty-acid-oxidation axis independently of exercise training confounds.
How is SLU-PP-332 reconstituted and stored for laboratory research?
Because SLU-PP-332 is a small molecule with limited aqueous solubility, reconstitution differs from peptide protocols. Published research and supplier documentation typically recommend preparing a concentrated stock solution in anhydrous DMSO (often 10-50 mM), which is then diluted into appropriate aqueous vehicles for research use. For cell-culture work, DMSO stocks are diluted into medium with final DMSO concentrations kept below 0.1 percent to avoid solvent artifacts. For in vivo rodent research, formulations typically combine DMSO with co-solvents such as PEG-400, cremophor, or cyclodextrins to maintain solubility. Solid SLU-PP-332 should be stored at -20 degrees C, sealed, desiccated, and protected from light. DMSO stocks are best stored at -80 degrees C in small aliquots to avoid repeated freeze-thaw cycles, which can precipitate the compound. Reconstitute for research only, and verify batch-specific solubility guidance from the supplier’s certificate of analysis before designing research protocols.
How does SLU-PP-332 compare to peptide-based research compounds in longevity research?
SLU-PP-332 sits in a distinct research category from peptide-based longevity compounds despite frequent co-discussion. Peptides such as MOTS-c act via cell-surface or cytosolic signaling (AMPK, folate cycle, mitochondrial-nuclear retrograde communication), whereas SLU-PP-332 directly engages nuclear receptors and modulates transcription. Published studies suggest both classes of research compounds converge on overlapping metabolic outcomes — mitochondrial biogenesis, improved oxidative capacity, favorable glucose and lipid handling — but through mechanistically distinct entry points into the network. Preclinical research indicates this means the two classes can be useful as complementary research probes of metabolic biology rather than direct substitutes. For investigators building a broader view of this field, our longevity peptides guide covers related research compounds including MOTS-c, Epithalon, and GHK-Cu, while SLU-PP-332 represents the small-molecule ERR-agonist arm of the exercise-mimetic research landscape.
Frequently Asked Questions
Is SLU-PP-332 safe for human use?
SLU-PP-332 is a research chemical. It is not approved for human or animal consumption in any jurisdiction, has not been evaluated by the FDA, and has not completed human clinical trials. All published SLU-PP-332 studies are preclinical, conducted in cell-culture systems or rodent models. Published studies suggest the compound has an interesting preclinical research profile, including tolerability in short-term rodent studies, but tolerability in controlled animal research does not translate to human safety. Preclinical research indicates that any human translation would require formal clinical development, including proper pharmacokinetic characterization, toxicology, and regulated trials. SLU-PP-332 is supplied strictly for laboratory research use. Investigators should handle it using standard chemical hygiene practices — gloves, eye protection, fume hood where appropriate — and follow institutional biosafety and chemical-handling protocols. It is not intended, approved, or sold for human or animal consumption.
How does SLU-PP-332 differ from GW501516 (cardarine) in research?
SLU-PP-332 and GW501516 are both small-molecule research compounds studied for exercise-mimetic-like effects, but they operate via different nuclear receptor targets. GW501516 is a PPAR-delta agonist, while SLU-PP-332 is an ERR pan-agonist. Published studies suggest both compounds produce overlapping downstream outcomes — increased running capacity, mitochondrial biogenesis, enhanced fatty acid oxidation — because both feed into PGC-1-alpha-driven oxidative programs. Preclinical research indicates they do so through distinct upstream entry points: PPAR-delta directly, versus ERR pan-agonism with ERR being a PGC-1-alpha partner. GW501516 development was discontinued due to carcinogenicity findings in long-term rodent toxicology, which is frequently cited as part of the research context. SLU-PP-332 does not have an equivalent published long-term toxicology profile. Both are strictly research chemicals, not approved for human or animal consumption.
What tissues express ERR-alpha, ERR-beta, and ERR-gamma in research models?
Published studies suggest the three ERR isoforms have overlapping but distinct tissue expression patterns. ERR-alpha is broadly expressed but particularly abundant in high-energy-demand tissues including skeletal muscle, heart, brown adipose, kidney, and liver. ERR-beta has a more restricted distribution, with notable expression in placenta, eye, and specific brain regions, and is required for embryonic development in rodent models. ERR-gamma is also broadly expressed with high levels in heart, kidney, brain, and developing skeletal muscle. Preclinical research indicates SLU-PP-332’s pan-agonist activity engages all three isoforms, meaning its in vivo effects reflect the combined tissue-level outputs of all ERR subtypes. This broad activity profile is useful for studying total ERR contribution to metabolic phenotypes in rodent research, though it limits the ability to isolate subtype-specific biology compared with selective ERR-alpha or ERR-gamma research tools.
Does SLU-PP-332 work in the absence of exercise in research models?
Yes — the defining research observation from published preclinical studies is that SLU-PP-332 produces exercise-overlapping transcriptional and phenotypic outcomes in sedentary rodent models without any training stimulus. Published studies suggest treated sedentary mice show increased treadmill running capacity, elevated mitochondrial content in skeletal muscle, shifts toward oxidative fiber-type gene expression, and reduced fat-mass gain on high-fat diets relative to vehicle-treated controls. Preclinical research indicates these effects occur at doses that do not require concurrent exercise interventions. That said, published studies suggest that SLU-PP-332 does not replicate every benefit of exercise — cardiovascular conditioning, tendon and bone adaptation, and neurological effects are not captured by pharmacological ERR activation. The research utility of SLU-PP-332 is as a tool for dissecting ERR-dependent metabolic adaptations, not as a clinical substitute for physical activity.
What are common reconstitution solvents for SLU-PP-332 research protocols?
Because SLU-PP-332 is poorly water-soluble, standard peptide reconstitution solvents such as bacteriostatic water are not appropriate. Published research and supplier documentation typically recommend anhydrous DMSO as the primary stock solvent, with concentrations commonly in the 10-50 mM range depending on desired working concentration. For in vitro cell-culture applications, DMSO stocks are diluted into culture medium with final DMSO concentrations kept below 0.1 percent to minimize solvent effects. For in vivo rodent research, combinations of DMSO with PEG-400, cremophor EL, cyclodextrins, or similar co-solvents are used to improve aqueous dispersibility. Preclinical research indicates formulation choice can meaningfully affect compound bioavailability in rodent studies, so investigators should review published protocols and supplier documentation for any batch. Reconstitute for research only, store DMSO stocks at -80 degrees C in small aliquots, and minimize freeze-thaw cycles to preserve compound integrity.
How should SLU-PP-332 be stored to maintain research-grade stability?
Solid SLU-PP-332, as supplied in research-grade lyophilized or solid form, should be stored at -20 degrees C, sealed in its original vial, desiccated, and protected from light. Published peptide and small-molecule storage guidance suggests these conditions typically maintain stability for extended periods, and suppliers generally provide a shelf-life estimate on the certificate of analysis. Once dissolved in DMSO to form a stock solution, long-term storage is best achieved at -80 degrees C in small, sterile aliquots of low-binding tubes. Repeated freeze-thaw cycles can cause compound precipitation or degradation and should be minimized. Preclinical research indicates that working solutions diluted into aqueous buffer for cell-culture or in-vivo research should be prepared fresh rather than stored, because dilution into aqueous medium reduces solubility and can produce reproducibility problems. Always verify batch-specific storage recommendations on the supplier’s certificate of analysis before designing long-running research protocols.
Where does SLU-PP-332 fit in the broader longevity and metabolic research landscape?
SLU-PP-332 occupies a specific niche in longevity and metabolic research: it is a small-molecule, ERR-targeted, exercise-mimetic research probe. Published studies suggest it complements rather than replaces other research tools in the same broad field. Peptides like MOTS-c engage AMPK signaling from a mitochondrial-derived angle. Senolytics target senescent-cell clearance. Caloric-restriction mimetics (metformin, rapamycin analogs) act through AMPK and mTOR respectively. Preclinical research indicates SLU-PP-332’s value is in directly probing the ERR-PGC-1-alpha axis of oxidative metabolism, a node that other compounds reach only indirectly. For researchers mapping the exercise-mimetic and mitochondrial-health landscape, SLU-PP-332 provides a clean pharmacological handle on ERR biology. Our longevity peptides guide covers related research compounds and provides broader context for how these pathways intersect in contemporary laboratory research.
Research-Grade SLU-PP-332
Peptideware supplies SLU-PP-332 5 mg as a research-grade solid for laboratory use. Each unit is intended for reconstitution in appropriate research solvents (typically DMSO stock solutions) and use in controlled research settings following standard small-molecule handling protocols. Review the product page for current specifications, batch documentation, and laboratory-only terms of sale.
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Research disclaimer: All products are intended for laboratory and research purposes only. Not for human or animal consumption. These statements have not been evaluated by the FDA.