Key Takeaways: Ashwagandha (Withania somnifera) has been shown in clinical trials to significantly reduce cortisol levels, improve sleep quality, and enhance physical performance. Here's what the peer-reviewed evidence actually says.
Ashwagandha has been a cornerstone of Ayurvedic medicine for over 3,000 years. Known as "Indian ginseng" and classified as a rasayana herb (meaning it promotes longevity and rejuvenation), this root has attracted serious scientific attention in recent decades.
What Does the Research Show?
Multiple randomised controlled trials have investigated ashwagandha's effects on stress, cognition, and physical performance. A landmark 2012 study published in the Indian Journal of Psychological Medicine found that adults who took 300mg of ashwagandha root extract twice daily experienced a 44% reduction in stress scores and a 27.9% reduction in serum cortisol levels compared to placebo.
Sleep Quality Benefits
A 2019 randomised controlled trial published in Medicine found that participants taking ashwagandha root extract (300mg twice daily) showed statistically significant improvements in sleep quality, sleep onset latency, and total sleep time compared to the placebo group. Participants with insomnia showed particularly marked improvements.
Safety & Dosage
Clinical trials have used doses ranging from 250mg to 600mg of root extract per day, typically taken as 300mg twice daily with meals. Ashwagandha is generally well-tolerated, though it should be avoided during pregnancy and by individuals with thyroid conditions unless supervised by a healthcare provider.
Disclaimer
This article is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare provider before starting any supplement regimen.
Bottom Line
The evidence for ashwagandha's adaptogenic effects — particularly for stress, cortisol reduction, and sleep quality — is among the strongest of any herbal supplement. Its millennia-long traditional use is increasingly supported by well-designed clinical research.
Dr. Rita Osei, ND
Naturopathic Doctor · Leyi Wellness Team
Dr. Osei specialises in herbal medicine and integrative health. She has contributed to peer-reviewed research on adaptogenic herbs and botanical supplements.