How It Works
Withanolides (active compounds) modulate HPA axis (hypothalamic-pituitary-adrenal) → reduced cortisol. GABA-mimetic activity → anxiolytic effect. Increases LH (luteinizing hormone) → increased testosterone production. Antioxidant via Nrf2 pathway activation.
Dosage & Timing
Dosage Guide
Daily Dose300-600 mg
TimingSplit AM/PM with food. Standardized to 5% withanolides (KSM-66 or Sensoril).
BioavailabilityKSM-66 (root only extract) — best researched. Sensoril (root+leaf) — more sedating, better for sleep. Take with fat-containing meal for absorption.
Optimal Timing
Take with food. Consistency matters more than timing for most supplements.
Blood Markers to Monitor
- Cortisol (AM + PM)
- DHEA-S
- TSH, Free T4, Free T3 (if thyroid concerns)
- Liver enzymes (ALT, AST — rare elevations)
Cycling & Duration
Some sources recommend cycling: 6-8 weeks on, 2-4 weeks off. This may prevent tolerance and maintain HPA axis sensitivity. Not universally agreed upon.
Best Forms (Ranked)
KSM-66 (root extract) — ★★★★★
Most researched. 5% withanolides. Best for sports/energy. Our top pick.
Sensoril (root+leaf) — ★★★★☆
8-10% withanolides. More sedating. Better for sleep/anxiety. Good for evening use.
Standard powder (non-standardized) — ★★☆☆☆
Variable potency. Hard to dose. Not recommended.
Evidence-Based Benefits
- 15-28% cortisol reduction
- 14-17% testosterone increase in stressed men
- Improved VO2 max (aerobic capacity)
- Reduced anxiety scores (HAM-A)
- Improved sleep quality
- Increased muscle strength (7-10% in studies)
Side Effects & Safety
- GI discomfort at high doses
- Thyroid stimulation (caution with hyperthyroid)
- Sedation at high doses
- Rare: liver enzyme elevation
✅ Good For
- High-stress individuals
- Athletes in heavy training blocks
- Men with stress-related low T
- Anxiety support
- Sleep improvement
⚠️ Skip If
- Pregnancy/breastfeeding
- Hyperthyroidism
- Autoimmune conditions (immune-stimulating — consult doctor)
- Upcoming surgery (stop 2 weeks prior)
Stacks Well With
Recommended Products
Affiliate links — we may earn commission.
KSM-66 Ashwagandha by Nootropics Depot
★★★★★ 4.7/5
Physician's Choice Ashwagandha
★★★★★ 4.5/5