Convert between KSM-66, Sensoril, and generic ashwagandha extracts by withanolide content. “1,500 mg ashwagandha” on a label tells you almost nothing — the standardized extract amount (with withanolide %) is what matters. Math, not medical advice.
Your goal + product
600 mg/day
Recommended extract dose for selected goal
30 mg/day
Equivalent withanolide content (the active compound dose)
Extract reference — withanolide standardization
| Extract | Withanolide % | Standard trial dose | Trade-offs |
|---|---|---|---|
| KSM-66 (Ixoreal) | 5% | 600 mg/day (300 × 2) | Most RCTs (10+); root-only; full-spectrum; mild taste |
| Sensoril (Natreon) | 10% | 125-250 mg/day | Root + leaf; higher withanolide; some anxiety RCTs |
| Generic 5% withanolides | 5% | 600 mg/day | Cheaper than KSM-66; quality varies; less RCT support |
| Generic 2.5% withanolides | 2.5% | ~1,200 mg/day | Need 2× dose vs 5% extracts; common in cheaper products |
| Generic 1.5% withanolides | 1.5% | ~2,000 mg/day | Very dilute; large pill burden; often labeled “high potency” |
| Plain root powder (no extraction) | ~0.3% (varies) | 3,000-5,000 mg/day | Traditional Ayurvedic form; large doses needed; significantly under-dosed vs trial protocols |
KSM-66 vs Sensoril — when each fits
- KSM-66: root-only extract, water-extracted, 5% withanolides. Best RCT evidence overall (stress/cortisol, sleep, testosterone, athletic performance). 300-600 mg/day standard. Mild taste; preferred for stacking with other adaptogens.
- Sensoril: root + leaf, higher 10% withanolide standardization. Best evidence for anxiety (Auddy 2008). Lower dose (125-250 mg/day). Often more sedating — better for evening dose.
- Generic extracts: 5% withanolides is the threshold for “comparable to KSM-66” on paper, but third-party testing often shows actual content lower than label claim. Use brands that publish COA (certificate of analysis).
- Plain root powder: the original Ayurvedic form. Effective doses are 5-10g/day (rasayana traditional use). Most consumer “ashwagandha capsules” with root powder under-dose massively.
Common label tricks to watch
- “1,500 mg ashwagandha”: usually means 1,500 mg of low-grade root powder (3 mg withanolides) — NOT 1,500 mg standardized extract. Look for “standardized to X% withanolides.”
- “Full-spectrum”: marketing term, no standardization. Could mean anything.
- “Proprietary blend”: hides individual ingredient doses. Usually under-dosed.
- “With BioPerine”: 5 mg black pepper extract enhances absorption of some compounds. Not specifically validated for ashwagandha but doesn’t hurt.
- Stated dose vs actual: ConsumerLab and Labdoor tests have found significant deviation between labeled and actual withanolide content. Trust brands with third-party COA links.
Drug interactions (review before starting)
- Thyroid medication (levothyroxine): ashwagandha can raise T4. May reduce levothyroxine dose needed. Coordinate with endocrinologist; case reports of thyrotoxicosis.
- Immunosuppressants (tacrolimus, cyclosporine, MTX): ashwagandha is immunostimulant — contraindicated.
- Sedatives / benzodiazepines / alcohol: additive sedation. Avoid combining.
- Diabetes meds: mild glucose-lowering effect — monitor for hypoglycemia if on insulin/sulfonylureas.
- Blood pressure meds: additive hypotension possible.
- Pregnancy: CONTRAINDICATED — abortifacient effect at high doses in animal studies.
- Autoimmune conditions (lupus, MS, RA, Hashimoto’s): immunostimulant action may worsen — use only under specialist supervision.