SLU-PP-332

Mechanism

SLU-PP-332 is a compound that activates the same molecular pathways your body uses during exercise, essentially tricking your muscles into thinking they are working out. It targets receptors called ERRs that control how muscles use energy and build endurance, leading to increased fat burning and improved exercise capacity in animal studies. While not a traditional peptide, it represents a new class of molecules that could help people who cannot exercise due to disease or disability.

Effects

## Musculoskeletal System [Tier 2 - Animal Data] - Activates estrogen-related receptor (ERR) alpha, beta, and gamma transcription factors, mimicking transcriptional changes induced by endurance exercise - Increases oxidative (Type I) muscle fiber proportion and fatigue resistance in sedentary animal models - Upregulates mitochondrial biogenesis genes (PGC-1a, TFAM, NRF1) in skeletal muscle without physical activity - Enhances fatty acid oxidation capacity in myocytes by 40-60% in preclinical models ## Metabolic System [Tier 2 - Animal Data] - Shifts substrate utilization toward fatty acid oxidation, reducing reliance on glycolysis - Reduces body fat accumulation in high-fat-diet rodent models without caloric restriction or exercise - Improves glucose tolerance and insulin sensitivity through enhanced mitochondrial function - May reduce hepatic lipid accumulation through increased beta-oxidation gene expression ## Cardiovascular System [Tier 3 - Mechanistic/Early Preclinical] - ERR activation in cardiac tissue supports mitochondrial health and oxidative phosphorylation - Theoretical cardioprotective benefits through improved cardiac energetics, though direct cardiac studies are limited - May improve endothelial function indirectly through metabolic improvements ## Central Nervous System [Tier 3 - Theoretical] - Exercise-mimetic transcriptional programs may confer neuroprotective benefits similar to actual exercise (BDNF upregulation, neurogenesis) - ERR gamma is expressed in brain tissue; activation could support neuronal energy metabolism - No direct CNS studies published as of early 2026

Practitioner Guide

## Clinical Context SLU-PP-332 is a research compound with no human clinical data. It represents a novel class of exercise mimetics targeting ERR transcription factors rather than AMPK (as with AICAR) or PPARdelta (as with GW501516). It is NOT currently available through compounding pharmacies and remains strictly a research tool. ## Who Is Asking About This Typically biohackers and longevity enthusiasts who cannot exercise due to injury, disability, or are looking for additive benefits on top of training. Manage expectations: this is years from clinical use. ## Theoretical Dosing (Research Context Only) - No human dosing established - Rodent studies used oral dosing in the range of 25-50 mg/kg, which does NOT translate directly to human equivalent doses - Not available in injectable peptide form — this is an oral small molecule, not a peptide in the traditional sense ## What Practitioners Should Know - This is frequently confused with peptides but is actually a small-molecule ERR agonist developed at Washington University in St. Louis - No safety data in humans whatsoever - The appeal is the concept of "exercise in a pill" — useful for patient education about the ERR pathway - Patients asking about this are often good candidates for actual exercise-mimetic peptides with more data: MOTS-c, 5-amino-1MQ, or AOD 9604 - The ERR pathway is upstream of many exercise adaptations, making it theoretically powerful but also theoretically risky (cancer concerns with growth-promoting transcription factors) ## Realistic Timeline - Phase I human trials: not yet initiated as of early 2026 - Clinical availability: likely 5-10 years minimum if development continues

Dosing Protocols

Contraindications & Cautions

• hard stop — Pregnancy
  No human safety data. Preclinical research compound with no clinical trials. ERR agonism alters metabolic gene programs in ways that could impact fetal development.
  Action: Do not use during pregnancy.
• hard stop — Breastfeeding
  No human safety data. Preclinical compound only. Do not use during lactation.
  Action: Do not use while breastfeeding.
• hard stop — Under 18 years of age
  Peptide protocols are not designed for pediatric use. No human safety data exists for this compound.
  Action: Do not provide to individuals under 18.
• caution — General use
  SLU-PP-332 has NO human safety data. It is a preclinical research compound with only animal study data. No clinical trials have been initiated. Human pharmacokinetics, toxicity, and long-term effects are completely unknown.
  Action: Use only with full informed consent regarding absence of human safety data. Extreme caution warranted. Medical supervision strongly recommended.
• caution — Active cancer
  ERR agonism promotes mitochondrial biogenesis and VEGF-mediated angiogenesis. Theoretical concern that enhanced metabolic and angiogenic activity could support tumor growth, though no direct evidence exists.
  Action: Avoid in patients with active cancer until human safety data is available.

Research Summary

## Tier 1 — No Human Data No human clinical trials have been conducted or registered for SLU-PP-332. ## Tier 2 — Animal Data (Primary Evidence Base) - Washington University (St. Louis) published foundational rodent studies showing ERR agonism reproduces exercise-induced gene expression changes in skeletal muscle - Mice treated with SLU-PP-332 showed increased running endurance (~70% improvement) without exercise training - High-fat diet models showed resistance to obesity and improved metabolic parameters - Muscle fiber-type switching toward oxidative fibers confirmed histologically ## Tier 3 — Mechanistic/In Vitro - ERR alpha/beta/gamma are orphan nuclear receptors with no known endogenous ligand - SLU-PP-332 is a synthetic agonist with pan-ERR activity - In vitro studies show dose-dependent upregulation of PGC-1a, cytochrome c oxidase, and fatty acid transport genes - Selectivity for ERR over estrogen receptors (ER-alpha, ER-beta) has been confirmed, reducing estrogenic side effect concern ## Evidence Gaps - Zero human pharmacokinetic, safety, or efficacy data - Long-term cancer risk unknown (ERR activation could theoretically promote certain malignancies) - Optimal dosing, bioavailability, and drug interactions completely undefined - No head-to-head comparisons with other exercise mimetics