Ashwagandha
Guides, research reviews, comparisons, product recommendations and FAQs for ashwagandha.
Where to buy on Amazon
Products discussed on this page. Outside the US the links open your local Amazon store where it carries the product; stock and price differ between stores. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Buying in the UK?
A UK retailer that ships within the UK. Price and stock change often; check them on the retailer's page. We earn a commission if you buy, at no extra cost to you.
Start with Ashwagandha
Ashwagandha Guide
Evidence-based beginner and intermediate guide.
Explore ->Best Ashwagandha Products
Ranked recommendations and affiliate product options.
Explore ->Ashwagandha Comparisons
Compare benefits, timing, dosage and alternatives.
Explore ->Ashwagandha FAQs
Practical answers to common questions.
Explore ->What the Research Says
Frequently Asked Questions
What is the best ashwagandha extract?
KSM-66 and Sensoril are the two clinically validated extracts. KSM-66 (full-spectrum root extract, 5% withanolides) has more RCT data on strength and cortisol. Sensoril (leaf+root, 10% withanolides) is preferred for sleep. For general use, KSM-66 at 300–600mg/day is the most researched form.
How long before ashwagandha works?
Most RCTs show meaningful effects on cortisol and stress at 8 weeks. Sleep benefits can appear in 2–4 weeks. Strength gains (when combined with resistance training) become measurable around 6–8 weeks. Consistency matters more than timing — take it daily.
Should I take ashwagandha in the morning or at night?
The clinical trials show benefits with either timing. For sleep, taking 300mg 1 hour before bed is supported by RCT data. For cortisol and performance, split dosing (morning + evening) or a single morning dose with food works well. Avoid taking on an empty stomach as it can cause mild GI discomfort.
Does ashwagandha increase testosterone?
Several RCTs show modest increases in testosterone in healthy men — typically 10–22% above baseline. The effect is thought to be indirect: cortisol suppression reduces stress-related testosterone inhibition. Not a replacement for addressing fundamental hormone issues, but meaningful as an adaptogen.
Is ashwagandha safe long-term?
Human trials up to 12 weeks show a good safety profile. Rare cases of liver injury have been reported (likely idiosyncratic, not dose-dependent). Not recommended during pregnancy. People with thyroid conditions should consult a doctor as ashwagandha may affect thyroid hormone levels. Cycle use (8 weeks on, 4 weeks off) is a conservative approach.