Ashwagandha
Withania somnifera — also known as Indian Ginseng or Winter Cherry.
One of the most studied adaptogens in Ayurvedic medicine, now backed by multiple clinical trials showing meaningful reductions in stress, cortisol, and anxiety markers.
Evidence Quality
Multiple double-blind, randomized controlled trials (RCTs) in humans. Effects on stress, cortisol, and anxiety are well-replicated. Evidence for athletic performance and thyroid support is promising but less consistent.
What Is Ashwagandha?
Ashwagandha is a small shrub native to India, the Middle East, and North Africa. Its root has been used for over 3,000 years in Ayurvedic medicine as a rasayana — a rejuvenating tonic believed to promote longevity and vitality.
The active compounds are withanolides — a group of steroidal lactones that appear to modulate the stress response, reduce cortisol secretion, and support GABA-A receptor activity (the same pathway targeted by anti-anxiety medications, though much more mildly). High-concentration root extracts (standardized to 5% withanolides) are significantly more effective than raw root powder.
Key Benefits
Stress & Cortisol Reduction
In a 2019 RCT (Chandrasekhar et al.), 240 mg/day of KSM-66 ashwagandha reduced perceived stress scores by 41% and serum cortisol by 22.2% over 60 days vs. placebo. This is one of the most replicated findings in adaptogen research.
Anxiety Reduction
A meta-analysis of 5 RCTs (Pratte et al.) found significant reductions in anxiety and depression scores with ashwagandha supplementation. Effects are comparable to low-dose anxiolytics without sedation.
Sleep Quality
300–600 mg/day showed improved sleep onset, total sleep time, and sleep quality in insomnia patients (2021 RCT). Likely mediated by triethylene glycol content and mild GABAergic activity.
Physical Performance & Testosterone
In healthy men, 300 mg twice daily increased VO₂ max, muscle strength (bench press, leg extension), and testosterone levels (+17% in one 8-week trial). Secondary benefit; effects vary significantly by individual.
Cognitive Function
Small but significant improvements in memory, executive function, and reaction time in healthy adults supplementing 300 mg/day (Choudhary et al., 2017).
Dosage & How to Take It
Effective Dose Range
300–600 mg/day
Recommended Form
Root extract — standardized to ≥5% withanolides
Best Brands / Forms
KSM-66®, Sensoril® (both clinically studied)
When to Take
With meals; can split into 2 doses. Evening dose may improve sleep.
Onset of Effects
4–8 weeks for full benefits
Cycle Recommendation
8–12 weeks on, 4 weeks off (some practitioners recommend)
Avoid raw root powder — typically much lower withanolide content and variable quality. Look for a standardized extract with a third-party COA.
Contraindications & Cautions
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Pregnancy: Do not use. Ashwagandha has traditional use as an abortifacient at high doses. Avoid during pregnancy and breastfeeding.
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Thyroid conditions: May increase thyroid hormone levels. Use caution if you have hyperthyroidism or are on thyroid medication — monitor thyroid function with your doctor.
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Autoimmune disease: Ashwagandha may stimulate immune activity. Avoid or use with medical supervision in conditions like Lupus, Hashimoto's, or Rheumatoid Arthritis.
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Sedative medications: Potential additive sedation with benzodiazepines, barbiturates, and other CNS depressants. Consult your doctor.
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Rare liver concerns: Several case reports of liver injury at high doses (>1,000 mg/day) or prolonged use. Keep to recommended doses and cycle usage.
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Nightshade family: Belongs to Solanaceae. Those with nightshade sensitivities may experience mild reactions.
What to Look for When Buying
- Root extract standardized to ≥5% withanolides (not leaf extract or raw powder)
- Clinically studied branded ingredient: KSM-66® (full-spectrum) or Sensoril® (more sedating)
- Third-party tested for heavy metals and contaminants (COA available)
- Minimum 300 mg per serving — many low-quality products underdose significantly
- Capsule preferred over gummy (dose accuracy and no added sugars)
Where to Buy
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Amazon — KSM-66 Ashwagandha (recommended form)
Root extract, 600 mg, standardized to 5% withanolides. Third-party tested.
iHerb — Multiple KSM-66 Options
Large selection of standardized root extracts. Competitive pricing, ships internationally.
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