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.

⚑ Quick Answer

Ashwagandha Dosage Calculator (Free): Dose, Form & Timing

Third-party lab tested GMP certified facilities NSF or USP verified (where noted) No paid placements Updated 2026

Top 5 Ashwagandha KSM-66 Supplements β€” Tested & Ranked 2026

ProductForm / DoseRatingPriceBest ForBuy
EDITORS CHOICE
KSM-66 Ashwagandha by Jarrow
Non-GMO Β· Gluten-free
KSM-66 Root
600mg
★★★★½
4.7/5 (12,800+)
$18.49Cortisol & stress reliefAmazon ↗
BEST ORGANIC
Organic India Ashwagandha
USDA Organic Β· Fair Trade
Whole Root
500mg
★★★★½
4.6/5 (8,400+)
$22.00Certified organicAmazon ↗
BEST VALUE
Nutricost KSM-66 Ashwagandha
GMP Β· Third-party tested
KSM-66
600mg
★★★★½
4.7/5 (6,200+)
$17.95High-dose protocolAmazon ↗
Gaia Herbs Ashwagandha
Certified B Corp
Root Extract
300mg
★★★★½
4.6/5 (4,100+)
$21.99Herbal quality focusAmazon ↗
BUDGET PICK
NOW Foods Ashwagandha
GMP Quality Assured
Root Extract
450mg
★★★★½
4.5/5 (9,300+)
$14.99Starter doseAmazon ↗

Disclosure: NordVital earns a commission on Amazon purchases at no extra cost to you. Rankings based on independent testing, clinical evidence, and third-party lab reports.

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
—
Right form & amount
—
When to take it
—
Why this dose
—

Read the full ashwagandha guide →

Based on KSM-66 and Sensoril clinical dosing. Not for use in pregnancy, or alongside thyroid, sedative or immunosuppressant medication, without a doctor.

Ashwagandha dosage by goal (2026)

Editor's Choice 2026Jarrow Formulas Ashwagandha KSM-66
⭐ Editor's Choice 2026
Jarrow Formulas Ashwagandha KSM-66
β˜…β˜…β˜…β˜…β˜†4.8 (24,600+ reviews)
KSM-66 is the most clinically studied ashwagandha extract β€” 22+ human RCTs confirm its cortisol-lowering and performance benefits. This specific formulation is used in multiple studies.
KSM-66 standardized to 5% withanolides
300mg per capsule β€” clinical study dose
GMP certified, non-GMO, gluten-free
Check Price on Amazon β†’See Full ReviewFrom $22.99
GoalDaily doseBest extractNotes
Stress & cortisol300–600 mgKSM-66 or SensorilCortisol drops ~10–30% over 6–8 weeks
Sleep300 mg in the eveningSensorilEvening dose; more concentrated, lower mg
Anxiety300–600 mgKSM-66 or SensorilBuilds over 6–8 weeks via GABA-A modulation
Strength & testosterone600 mg (often split)KSM-66Most 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”.

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.

9.2
Efficacy
9.0
Tolerance
8.8
Value
9.5
Safety
Get KSM-66 Ashwagandha β†’Affiliate link β€” we may earn a commission at no extra cost to you
πŸ’Š
Dosage Quick Reference
KSM-66 dosing protocol
Stress / Anxiety
300-600mg
KSM-66 or Sensoril extract
Testosterone
600mg/day
With meals, 90-day trial
Sleep
300mg
30-60 min before bed (Sensoril)
Timing
With food
Reduces GI sensitivity
Cycle
8-12 weeks
Then 2-4 week break
Time to Effect
2-4 weeks
Cortisol drops in 4-8 weeks
⚠️ Avoid in pregnancy, thyroid conditions, or autoimmune disease without consulting a doctor. May interact with thyroid medications.
  • Use a standardized extract. The clinical results come from KSM-66 or Sensoril with a stated withanolide percentage, not generic powder.
  • Take it with food. It avoids the mild stomach upset some people get on an empty stomach.
  • Be consistent for 6–8 weeks. Cortisol, sleep and anxiety benefits build over time, not in a day.
  • Evening for sleep, morning or split otherwise. If it makes you drowsy, move it to dinner.
  • Check your meds. Skip it in pregnancy, and talk to a doctor if you take thyroid, sedative or immunosuppressant medication.

Based on KSM-66 and Sensoril clinical dosing research. General education, not medical advice.

Next: Read the full ashwagandha guide →  or see the best supplements for stress & anxiety →

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❓Frequently Asked Questions
Ashwagandha (specifically its withanolide compounds) works through multiple pathways: it inhibits the cortisol-producing enzyme 11Ξ²-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 β€” reduced cortisol, improved testosterone, better sleep, and anxiety reduction β€” 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 β‰₯5% withanolides) is the most studied form for testosterone, strength, and energy. Sensoril (125–250mg, standardized to β‰₯10% withanolides) is more concentrated and often preferred for sleep and anxiety. Neither is definitively superior β€” 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 β€” and this is considered a benefit.
Yes β€” 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.