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Ashwagandha KSM-66

The most clinically studied adaptogen on the market. KSM-66 is the specific extract with the strongest evidence for cortisol reduction, stress resilience and sleep improvement.

Strong Evidence Stress & Cortisol Sleep Not for Pregnancy
Daily Dose
300–600mg
KSM-66 extract
Best Form
KSM-66
Most studied extract
When to Take
Morning
With food
Time to Work
4–8 weeks
Full effect
Cortisol Drop
15–25%
In RCTs
Monthly Cost
€18–35
Mid range
What is it

What is Ashwagandha KSM-66?

Ashwagandha (Withania somnifera) is an adaptogen — a plant that helps the body adapt to and resist stress. KSM-66 is a specific patented root extract developed in India, standardized to contain at least 5% withanolides — the active compounds responsible for its effects.

The KSM-66 designation matters. Many ashwagandha products on the market are cheap root powders with minimal active compounds. KSM-66 has over 24 clinical studies specifically on this extract, making it the most evidence-backed form available.

Benefits

What the Research Shows

Who Needs It

Is Ashwagandha Right for You?

✓ Take it if you...
  • Have high stress levels or feel chronically overwhelmed
  • Struggle with sleep despite being tired
  • Want to support testosterone naturally
  • Are an athlete wanting to improve recovery and endurance
  • Experience anxiety without wanting pharmaceutical intervention
⚠ Do NOT take if you...
  • Are pregnant or breastfeeding — ashwagandha is contraindicated
  • Have thyroid conditions — it can affect thyroid hormone levels
  • Take immunosuppressant medications
  • Have autoimmune conditions — it stimulates immune function
Dosing Protocol

How to Take Ashwagandha

Standard Protocol Most people
300–600mg
KSM-66 extract daily, taken with morning food. Lower dose (300mg) is effective for stress and sleep. Higher dose (600mg) is used in studies for testosterone and athletic performance.
💡 Key point

Always check the label says KSM-66 or Sensoril specifically. Generic "ashwagandha root powder" products may contain very little active withanolide content despite the same headline dose.

KSM-66 vs Other Forms

Why KSM-66 Specifically?

KSM-66 — Full-spectrum root extract, 5%+ withanolides, 24+ clinical studies, best evidence for stress, cortisol, and testosterone. The gold standard.

Sensoril — Root and leaf extract, higher withanolide content (10%), some studies showing good efficacy, typically better for sleep specifically.

Generic ashwagandha powder — Variable withanolide content, minimal clinical research on specific products. Much cheaper but results are inconsistent.

For most people, KSM-66 at 300–600mg is the right choice. If sleep is your primary goal, Sensoril is a reasonable alternative.

Side Effects

Safety & Side Effects

Ashwagandha is well-tolerated at standard doses in most healthy adults. Reported side effects are generally mild:

⚠ Thyroid interaction

Ashwagandha can increase T3 and T4 thyroid hormones. If you have hypothyroidism or hyperthyroidism, or take thyroid medication, consult your doctor before using.

Recommended Products

What to Buy

KSM-66 Ashwagandha by Jarrow
Certified KSM-66, 300mg per capsule, clean label
Best value
Thorne Botanical Adaptogens
KSM-66 with additional adaptogens, NSF certified
Most trusted
Pure Encapsulations Ashwagandha
KSM-66 600mg, hypoallergenic, third-party tested
Best quality
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