Ashwagandha is a root extract long used as a rejuvenating tonic. Its strongest, most repeatable evidence is lowering the body's main stress hormone and easing stress and anxiety, with a smaller benefit for sleep. Moderate evidence supports strength, fitness, memory, and, in men, inconsistent testosterone gains. Rare liver injury and thyroid shifts warrant care. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Morning serum cortisol | ~10–15 µg/dL | Tracks the primary stress-axis effect |
| Thyroid-stimulating hormone (TSH) | ~1.0–2.0 mIU/L | Detects thyroid over- or under-stimulation |
| Free T4 and Free T3 | Mid-to-upper reference range | Confirms direction of any thyroid change |
| ALT and AST (liver enzymes) | ALT ~10–26 U/L; AST ~10–26 U/L | Screens for drug-induced liver injury |
| Total & Free Testosterone (men) | Total ~500–900 ng/dL; free in upper-normal | Tracks the male hormonal benefit |
| Fasting glucose / HbA1c | Glucose ~75–90 mg/dL; HbA1c <5.4% | Captures modest blood-sugar effects |
| High-sensitivity CRP | <1.0 mg/L | Reflects any anti-inflammatory effect |
Cadence: Baseline, re-check at ~8–12 weeks, then every 6–12 months during continued use, with earlier testing if symptoms arise