SLU-PP-332

What is SLU-PP-332? The exercise mimetic at a glance

SLU-PP-332 is a synthetic small molecule (CAS 303760-60-3) that acts as a so-called exercise mimetic (a substance that mimics the effects of exercise). It activates all three estrogen-related receptors (ERRalpha, ERRbeta, ERRgamma). These nuclear ERR receptors control the mitochondrial energy metabolism and are naturally stimulated in the body by endurance exercise. Although SLU-PP-332 is not structurally a peptide, the chemical is discussed in similar contexts within the peptide and biohacking scene.

SLU-PP-332 was developed by researchers around Thomas Burris at Saint Louis University (abbreviated 'SLU'). In preclinical animal studies, the substance activates the same genetic program in skeletal muscle as endurance training - completely without physical activity of the mice [1]. Observed effects include increased mitochondrial density, enhanced fatty acid burning (beta-oxidation), an increase in oxidative muscle fibers, and improved endurance performance.

All scientific evidence on SLU-PP-332 so far comes exclusively from animal and in-vitro cell models. There are no clinical human studies, no regulatory drug approval, and no validated dosage for humans. On the gray market, SLU-PP-332 is traded as an unregulated research chemical ('research compound').

How is SLU-PP-332 used and administered?

In all published animal studies, researchers administered SLU-PP-332 intraperitoneally (i.p., directly into the abdominal cavity) to mice [1][2]. The standard dose was 50 mg/kg body weight, given twice daily over a period of 12 to 28 days. This dosing range is based on earlier pharmacokinetic measurements by the research group [2].

SLU-PP-332 has minimal oral bioavailability and does not build up effective plasma levels after oral intake [5]. To overcome this drawback, the development team synthesized the orally available follow-up molecule SLU-PP-915, which produces comparable metabolic effects in rodents [5]. The original SLU-PP-332, on the other hand, strictly requires parenteral injection.

On the gray market, SLU-PP-332 is usually offered as a dry powder in glass vials (typically 5 mg or 10 mg), dissolved by users with BAC water and injected subcutaneously. This subcutaneous use is completely unstudied: There are no pharmacokinetic studies on s.c. administration, no data on bioavailability in humans, and no safety limits. Results from intraperitoneal mouse studies cannot simply be transferred to a subcutaneous injection in humans.

From vial to use: SLU-PP-332 reconstitution and dosing

SLU-PP-332 comes as a powder and is primarily dissolved in DMSO in the scientific lab (solubility 1-10 mg/ml) before being diluted for injections [3]. The practice common on the gray market of dissolving the powder directly with bacteriostatic BAC water is an experimental user practice without pharmacological backing. SLU-PP-332 dissolves significantly better in organic solvents like DMSO or ethanol than in purely aqueous media.

To illustrate the gray-market handling (without any recommendation): If a 5-mg vial is reconstituted with 2 ml of BAC water, the concentration is 2.5 mg/ml. On a 100-IU insulin syringe (1 ml total volume), one dosing unit of 10 tick marks (0.1 ml) equals exactly 0.25 mg of the active substance. Due to the lack of data on pharmacokinetics and species conversion of the mouse dose (50 mg/kg), the biological effect of such amounts in humans is scientifically completely unknown.

For detailed information on handling and reconstitution of peptide vials, check out the practical guides. An evidence-based dosage calculation is not possible due to the lack of human data. You can find more well-founded substance profiles in the peptide library - including MOTS-c, a mitochondrial peptide with a related approach as an exercise mimetic.

How does SLU-PP-332 work? Mechanism of action and receptor pathways

SLU-PP-332 acts as a synthetic pan-ERR agonist that binds and stimulates all three isoforms of the nuclear estrogen-related receptors (ERRalpha, ERRbeta, ERRgamma) - with the highest affinity for ERRalpha (EC50 = 98 nM compared to 230 nM for ERRbeta and 430 nM for ERRgamma) [1]. These nuclear transcription factors control signaling pathways for mitochondrial biogenesis, oxidative phosphorylation, and fatty acid burning.

Through ERR activation, SLU-PP-332 induces the same molecular adaptations in skeletal muscle cells as aerobic endurance training [1]. The central mechanisms include the following metabolic processes:

• Mitochondrial biogenesis: The number of cellular power plants increases, while existing mitochondria synthesize ATP more efficiently [1].
• Increased fatty acid oxidation: Muscle cells preferentially burn free fatty acids instead of muscle glycogen as their primary energy source [2].
• More oxidative type IIa muscle fibers: The phenotype shifts toward fatigue-resistant muscle fibers - analogous to structural training adaptations [1].
• Increased basal metabolic rate: The basal energy expenditure of the test animals rises measurably without modifying calorie intake [2].

In animal studies, these metabolic changes occur purely pharmacologically, because SLU-PP-332 directly triggers the cellular training cascade at the gene level.

What do the studies on SLU-PP-332 show?

All published research on SLU-PP-332 consists of preclinical animal and cell studies. The following comparison table summarizes the most important study data and dosages from rodent models:

Metabolism, fat loss and obesity [2]: In diet-induced obese mice, SLU-PP-332 reduced body weight and body fat percentage without reducing food intake. Glucose tolerance and insulin sensitivity improved significantly, while triglycerides and cholesterol levels dropped - consistent effects were also seen in the ob/ob obesity model.

Endurance increase and muscle strength [1]: Treated mice achieved significantly longer running times and distances on the treadmill. In parallel, grip strength and the relative proportion of oxidative type IIa fibers in skeletal muscle increased.

Cardioprotection in heart failure [3]: In the TAC overload model, SLU-PP-332 improved left ventricular ejection fraction, inhibited myocardial fibrosis, and increased the survival rate by normalizing the mitochondrial heart metabolism.

Kidney function and aging processes [4]: In old laboratory mice, SLU-PP-332 reduced inflammatory markers, decreased pathological albuminuria, and revitalized the mitochondrial integrity of kidney tissue.

What risks and side effects are known?

In acute mouse studies (50 mg/kg 2x daily i.p. over 10 days), no visible toxic side effects occurred [1]. The blood count was normal, electrolytes were unchanged, and creatine kinase (a marker for muscle damage) showed no abnormalities - however, this does not allow reliable conclusions about toxicology or long-term safety in humans.

Doping relevance in competitive sports: A study from 2026 explicitly examined SLU-PP-332 and SLU-PP-915 for their doping potential and developed detection methods for doping controls [6]. This is a clear sign that these substances are classified as performance-enhancing. Athletes who must follow doping rules should avoid SLU-PP-332.

Contaminants on the gray market: Since SLU-PP-332 is not a GMP-certified drug, freely sold vials are not subject to independent quality control regarding purity, content, and sterility. For guidance on analyzing lab certificates, see the guide on protection when ordering / vendor radar.

What is still unknown about SLU-PP-332?

• No human studies: To date, there is not a single clinical phase I study in humans regarding safety, tolerability, or bioavailability.
• Lack of oral effectiveness: SLU-PP-332 is not sufficiently absorbed after oral intake [5]. The follow-up development SLU-PP-915 is orally effective, but it has also only been studied preclinically.
• Untested s.c. injection: The subcutaneous administration described in biohacking forums has not been studied in any animal model; dose-response relationships are completely missing.
• Unknown long-term effects: The maximum preclinical study duration was 8 weeks - chronic toxicities or receptor desensitization have not been researched.
• Unresolved interactions: Potential interactions with medications, dietary supplements, or signaling pathways in humans are entirely untouched.

As a molecular exercise mimetic, SLU-PP-332 provides fascinating preclinical insights into ERR receptor biology, but the gap to human medicine is enormous. Given the lack of clinical safety data, purchasing and injecting gray-market substances represents an incalculable self-experiment.