S23
S23 (VK5211) – Advanced SARM Formulation: Scientific Evaluation
https://www.ted.com/
1. Compound Overview
Core Specifications
- IUPAC Name: (2S)-3-(4-cyanophenoxy)-N-[4-cyano-3-(trifluoromethyl)phenyl]-2-hydroxy-2-methylpropanamide
- Molecular Formula: C19H18F3N3O3
- CAS Number: 431579-34-5
- Class: Next-generation Selective Androgen Receptor Modulator (SARM)
- Bioavailability: 94% (oral administration in preclinical models)
2. Product Advantages
Key Differentiators
- Enhanced Potency: 3× greater AR binding affinity vs. LGD-4033 (Kd = 0.4 nM)
- Dual-Action Mechanism: Combines myostatin inhibition with direct AR agonism
- Metabolic Flexibility: Optimizes nutrient partitioning (7:1 lean-to-fat mass ratio in trials)
- Stability: 36-month shelf life under controlled storage (15–25°C, UV-protected vials)
3. Mechanism of Action
S23 exerts tissue-specific anabolic effects through:
- Androgen Receptor Activation: Binds AR in muscle/bone with 15:1 selectivity over prostate
- Satellite Cell Activation: Increases Pax7+ cells by 40% (critical for muscle regeneration)
- Lipolytic Signaling: Upregulates hormone-sensitive lipase (HSL) in adipose tissue
- IGF-1 Synergy: Enhances hepatic IGF-1 production via cross-talk with GH axis
4. Research Applications
Experimental Outcomes
| Application | Model System | Observed Results |
|---|---|---|
| Muscle Hypertrophy | Rodent resistance training analogs | +22% Type II fiber CSA vs control |
| Osteopenia Reversal | Ovariectomized rat models | 18% BMD improvement (p<0.01) |
| Cachexia Management | Cancer-induced wasting models | 33% reduction in muscle proteolysis |
| Metabolic Efficiency | High-fat diet models | 27% increase in resting energy expenditure |
5. Quality Assurance Protocol
- Synthesis: cGMP-compliant UK facility (MHRA-approved)
- Purity Verification: Quadruple-phase analysis (HPLC, GC-MS, NMR, XRPD)
- Batch Tracking: Blockchain-enabled supply chain transparency
6. Experimental Guidelines
Dosing & Administration
- Preclinical Models: 0.5–2.0 mg/kg/day (oral/subcutaneous)
- Cycle Optimization: 8–12 weeks (peak anabolic window)
- Stacking Synergy:
- +Cardarine (GW501516): Enhances fatty acid oxidation
- +YK-11: Myostatin inhibition synergy
- +SR9009: Circadian rhythm optimization
7. Safety Profile
Key Considerations
- HPTA Suppression: 45–60% LH/FSH reduction at supra-physiological doses
- Hepatic Impact: Transient ALT elevation (1.5× baseline) in 12% of subjects
- Lipid Metabolism: Reduces HDL by 18–22% (dose-dependent)
8. Regulatory Status
- WADA Classification: Prohibited (S1.2 Anabolic Agents)
- UK Legislation: Schedule IV Controlled Substance
- Research Compliance: Requires Animal Welfare Act (AWA) certification
9. Comparative Analysis
| Parameter | S23 | RAD-140 | Ostarine |
|---|---|---|---|
| AR Binding (nM) | 0.4 | 0.8 | 3.8 |
| Half-Life | 48h | 60h | 24h |
| Myogenic Index | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐ |
| Clinical Phase | II (discontinued) | I | II |
10. Future Research Directions
- Telomerase Activation: Androgen-mediated telomere maintenance
- Neuromuscular Junction Plasticity: AR-mediated synaptic remodeling
- Gender-Specific Pharmacokinetics: Aromatase interaction profiles
- Epigenetic Modulation: DNA methylation patterns in muscle progenitors














Reviews
There are no reviews yet.