SLU-PP-332 for Muscle Growth - Quick Reference Sheet

SLU-PP-332 for Muscle Growth

Created on 09/13/2026 – Quick Reference based on Evidence Review created using AI4L / Opus 5 Audit

A synthetic compound that switches on control proteins in muscle cells, reproducing part of the signal endurance training sends. In mice it built more energy-producing structures but left muscle fibres thinner. No human has received it in a registered study, so no measurement of muscle size, strength or safety exists. What is sold today is unregulated laboratory powder. (Full Review)

Protocol

No human protocol exists
No human dosed in a reported study
No practitioner, clinic or guideline describes a human regimen; what exists is literature and vendor practice, not a validated schedule
Published animal regimen
50 mg/kg twice daily
Intraperitoneal, 7 to 15 days, for efficacy work in mice; 30 mg/kg for pharmacokinetics
Single versus split dosing
Split, morning and evening
Every positive animal result used split twice-daily dosing; the acute gene response peaks 1 to 3 hours after a dose
Time to effect
Endurance Gains
7 days
In mice. No human timeline exists for any endpoint
Fibre & Mitochondrial Remodelling
7 to 15 days
In mice, on twice-daily dosing
Acute Gene Response
Within 1 hour
In mice, after a dose; gone by 6 hours

Benefits

Contraindications
  • Active malignancy, personal history of hormone-receptor-positive breast cancer, or current endocrine therapy for it
  • First-degree relative diagnosed with hormone-receptor-positive breast cancer before age 50, or a known BRCA1 or BRCA2 variant
  • Pregnant or breastfeeding women, and anyone under 18
  • Liver impairment at Child-Pugh Class B or C
  • Chronic kidney disease at an eGFR below 30 mL/min/1.73 m²
  • Heart failure at New York Heart Association (NYHA) Class III or IV
  • Competitive athletes subject to anti-doping testing
Key Interactions
  • Receptor-blocking agents (tamoxifen, 4-hydroxytamoxifen, XCT790-class inverse agonists)
  • Narrow-therapeutic-index prescription drugs (warfarin, phenytoin, digoxin, tacrolimus)
  • Over-the-counter analgesics (acetaminophen, high-dose ibuprofen, naproxen, aspirin)
  • Mitochondrial-biogenesis supplements (nicotinamide riboside, nicotinamide mononucleotide, resveratrol, urolithin A, pyrroloquinoline quinone)
  • High-dose antioxidant supplements (vitamin C above 1 g, vitamin E above 400 IU, N-acetylcysteine)
  • Other interventions (endurance training, caloric restriction, resistance training)

Risk & Side Effects

  • Speculative: Cancer promotion through ERRα activation; counter-productive fibre remodelling; unknown chronic and human toxicity; unselective activation of ERRs outside muscle; contamination and unsterile injection of research-grade material

Monitoring

Marker Target Why
Alanine aminotransferase Under 20 U/L Hepatic clearance is extensive and the responsible enzymes are unidentified
Creatine kinase 40–150 U/L (men), 30–120 U/L (women) Detects muscle breakdown; unchanged in treated mice, so a rise is a genuine signal
Complete blood count All indices within reference, haemoglobin in the upper half The rodent safety readout was a normal blood count, the closest toxicity comparator available
Estimated glomerular filtration rate Above 90 mL/min/1.73 m² ERR activation acts directly on kidney mitochondria
Fasting insulin Under 5 µIU/mL Improved insulin sensitivity was the clearest metabolic effect in animals
Haemoglobin A1c 4.8–5.3% Captures glucose control over roughly three months
Lean body mass by dual-energy X-ray absorptiometry No established target; change from own baseline The goal endpoint, never measured on this compound
Grip strength Above 40 kg (men), above 25 kg (women) Functional muscle output; the one strength signal seen in mice
Prostate-specific antigen, men from 45 Under 1.0 ng/mL before 60, and stable year on year Cancer surveillance; this receptor's over-activity drives tumour progression

Cadence: Baseline before exposure; liver, muscle and blood-count panel at 4 and 12 weeks, then every 3 to 6 months; body composition and strength every 12 weeks; glucose and kidney filtration every 6 months; cancer screening per age and family history

Qualitative Assessment

  • Perceived effort during steady-state cardiovascular work at a fixed pace or power
  • Recovery between training sessions, and next-day readiness
  • Sleep quality, time to fall asleep and night waking
  • Appetite, and tolerance of cold, since fat oxidation and heat production shift together
  • Training motivation and adherence, which no laboratory value captures
  • Injection-site appearance, if the compound is injected