Milk thistle is a plant seed extract sold as a dietary supplement for liver support. Across many controlled trials it lowers raised liver enzymes and, in people with high blood sugar, improves glucose control and lowers inflammation markers. No effect on living longer or better has been shown. Where numbers are already good, nothing to improve. Main cautions: daisy-family allergy, and products that vary enormously in what they contain. (Full Review)
| Marker | Target | Why |
|---|---|---|
| ALT | Under 25 U/L (men), under 20 U/L (women) | The primary trial endpoint and the most sensitive marker of liver-cell stress |
| AST | Under 25 U/L | Confirms the ALT signal and, when disproportionately high, points to alcohol or muscle rather than liver fat |
| GGT | Under 25 U/L (men), under 20 U/L (women) | Tracks bile-duct stress, alcohol exposure, and oxidative load; often the earliest marker to shift |
| ALP | 50–90 U/L | Distinguishes a blocked-bile-flow pattern, relevant because the extract increases bile flow |
| Total bilirubin | 0.3–1.0 mg/dL | Detects any conjugation problem and provides context for the enzymes |
| HbA1c | Under 5.4% | Captures the best-supported effect outside the liver, average blood sugar over about three months |
| Fasting insulin | Under 5 µIU/mL | Detects insulin-resistance improvement earlier than glucose does |
| hs-CRP | Under 0.5 mg/L | Tracks the inflammatory outcome silymarin most reliably moves |
| Liver fat fraction (imaging) | Under 5% liver fat | The only endpoint that establishes structural rather than biochemical improvement |
| TSH | 0.5–2.0 mIU/L | Addresses the unresolved thyroid-transporter signal, relevant only on replacement therapy |
Cadence: Baseline panel before the first dose; liver enzymes and blood-sugar markers repeat at 12 weeks, then at 6 months, then every 6 to 12 months if continued. Weekly glucose self-monitoring covers the first month for users on insulin or a sulfonylurea. Liver fat imaging repeats no more often than annually.