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”.
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How to take ashwagandha
⭐ Our Verdict
Our Verdict on Ashwagandha KSM-66
Ashwagandha is one of the better-studied adaptogens. Trials consistently show a modest drop in cortisol; results for perceived stress are mixed and the testosterone evidence is limited (NIH). Choose an extract tested in trials (KSM-66, Sensoril or Shoden), use it for up to 3 months, and skip it if you have a thyroid or autoimmune condition, liver problems, or are pregnant.
In trials, the clearest effect of ashwagandha is a modest drop in the stress hormone cortisol (about 1.2 µg/dL on average in a 2025 meta-analysis of 7 trials). The NIH says some preparations may help with stress and insomnia, the evidence on anxiety is unclear, and the evidence for testosterone is limited. Laboratory studies suggest it may act on GABA receptors.
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 have more evidence than unstandardized powders.
There is no good evidence that ashwagandha causes weight gain, or that any weight change while taking it is muscle rather than fat.
Yes — ashwagandha has several important interactions. It may interact with medicines for diabetes and blood pressure, immunosuppressants, sedatives and anti-seizure drugs. The NIH does not recommend it for people with thyroid or autoimmune disorders, before surgery, or during pregnancy and breastfeeding. Always consult your doctor if you're on prescription medications.
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