Ashwagandha Dosage Calculator (Free): Dose, Form & Timing
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The quick answer: the clinical dose of ashwagandha is 300–600 mg of a standardized extract per day (KSM-66 or Sensoril). Use KSM-66 for strength and testosterone, Sensoril for sleep and anxiety, take it with food, and give it 6–8 weeks. The calculator below matches your goal, extract and timing to a specific dose.
Free Tool
Ashwagandha dosage calculator: dose, form and timing
Answer three questions and get an evidence-based ashwagandha dose, the right extract, and when to take it.
Stress & cortisol
Better sleep
Anxiety
Strength & testosterone
KSM-66
Sensoril
Not sure / generic
Morning
Evening
Twice a day
Your daily dose
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Right form & amount
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When to take it
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Why this dose
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The extract your answers point to
KSM-66 ashwagandhaRoot-only extract standardised to at least 5% withanolides. The most studied one.
Based on KSM-66 and Sensoril clinical dosing. Not for use in pregnancy, or alongside thyroid, sedative or immunosuppressant medication, without a doctor.
KSM-66 is the most clinically studied ashwagandha extract — 22+ human RCTs confirm its cortisol-lowering and performance benefits. This specific formulation is used in multiple studies.
Most strength/testosterone trials use KSM-66 with training
KSM-66 (root only, standardized to ≥5% withanolides) is dosed at 300–600 mg. Sensoril (root + leaf, ≥10% withanolides) is more concentrated, so it is dosed lower at 125–250 mg. Both beat unstandardized “ashwagandha powder”.
Disclosure: NordVital earns a commission on Amazon purchases at no extra cost to you. Picks are based on published research, label doses and third-party certifications; we do not lab-test products.
How to take ashwagandha
⭐ Our Verdict
Our Verdict on Ashwagandha KSM-66
Ashwagandha KSM-66 is one of the best-studied adaptogens available. The evidence for cortisol reduction, stress relief, and testosterone support in men is genuinely strong across multiple RCTs. The key is choosing a quality KSM-66 extract and committing to 8-12 weeks. Most people feel meaningful improvement in stress response within 3-4 weeks.
Ashwagandha (specifically its withanolide compounds) works through multiple pathways: it inhibits the cortisol-producing enzyme 11β-HSD1, modulates GABA-A receptors (reducing anxiety), lowers thyroid-stimulating hormone in hypothyroid conditions, and increases testosterone by stimulating LH production. The result is reduced cortisol (10–30%), improved testosterone, better sleep, and increased stress resilience.
Mild calming effects can appear within 1–2 weeks. Full adaptogenic benefits — reduced cortisol, improved testosterone, better sleep, and anxiety reduction — typically require 6–8 weeks of consistent daily use. Most clinical trials showing significant results run for 8–12 weeks.
Both are excellent standardized root extracts. KSM-66 (300–600mg, standardized to ≥5% withanolides) is the most studied form for testosterone, strength, and energy. Sensoril (125–250mg, standardized to ≥10% withanolides) is more concentrated and often preferred for sleep and anxiety. Neither is definitively superior — both are far better than unstandardized powders.
Ashwagandha does not cause weight gain directly. However, by reducing cortisol (which promotes fat storage) and improving testosterone, it may cause body recomposition: some users gain muscle and lose fat simultaneously. Any weight change is muscle gain, not fat — and this is considered a benefit.
Yes — ashwagandha has several important interactions. It may enhance the effects of sedatives, anxiolytics, and immunosuppressants. It raises thyroid hormone levels, which is problematic for hyperthyroid patients and those on thyroid medication. It should not be used during pregnancy (uterine stimulant). Always consult your doctor if you're on prescription medications.
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