Knowledge Content
#### 1. Core mechanism of liver damage
1. **Direct cytotoxicity**: 17α-alkyl metabolites generated during metabolism can damage liver cell mitochondria, leading to elevated ALT (alanine aminotransferase) and AST (aspartate aminotransferase). Clinical data show that after 2 weeks of 50mg/day users, about 60% had mild elevation of liver enzymes (1-2 times higher than normal values), and the proportion rose to 85% for those taking more than 100mg/day.
2. **Risk of cholestasis**: The drug can inhibit bile acid transporters and cause bile excretion disorders, which manifests as elevated serum bilirubin. Long-term use (more than 8 weeks) may cause jaundice, with an incidence of about 5%-8%.
#### 2. Risk of dose and cycle pattern
- **Short-term low dose (<50mg/day, <4 weeks)**: Liver enzyme abnormalities are mostly reversible, 90% can return to normal after 2 weeks of discontinuation, and there is no significant risk of fibrosis.
- **Long-term high dose (>100mg/day, >6 weeks)**: Repeated damage to liver cells may induce central lobular necrosis, and about 10% of users have fibrosis visible in liver biopsy, and it is more closely associated with individuals with low CYP3A4 enzyme activity (slow metabolism).
#### 3. Comparison of toxicity with other steroids
Compared with similar drugs, Winstrol has lower liver toxicity than Dianabol (Methandrostenolone), but higher than Anavar (Oxandrolone): At the same dose, it causes an increase in liver enzymes 2-3 times that of Anavar, but only 60% of Dianabol. This makes it a "relatively controllable but cautious" option - liver enzymes need to be monitored every 2 weeks when used, and taking it with liver protectors such as silymarin can reduce the risk of damage by 30%, but it is absolutely contraindicated for those with a history of liver disease.
