Ashwagandha for Stress and Anxiety

Multiple randomised controlled trials and a 2024 meta-analysis of 9 studies (558 participants) show that Ashwagandha (KSM-66) significantly reduces perceived stress, anxiety scores, and serum cortisol levels compared to placebo. Effects are most pronounced in people with elevated baseline stress. Evidence rating: ⭐⭐⭐⭐ Strong.

Why Ashwagandha Matters for Stress & Anxiety

Ashwagandha is one of the most researched adaptogens for helping the body manage physical and psychological stress. Chronic stress elevates cortisol, which can impair sleep, mood, immune function, and long-term metabolic health. Ashwagandha appears to modulate the hypothalamic-pituitary-adrenal (HPA) axis, helping to normalise cortisol output and reduce the subjective experience of stress and anxiety.

Key Benefits

  • Reduces perceived stress (PSS scores) and anxiety symptoms
  • Lowers serum cortisol levels in stressed adults
  • Improves resilience during periods of high workload or life stress
  • Supports better sleep quality secondary to reduced nighttime cortisol

Key Studies

Arumugam, V. et al. (2024) — Systematic review and meta-analysis of 9 randomised controlled trials (558 participants). Ashwagandha significantly reduced Perceived Stress Scale (PSS) scores, Hamilton Anxiety Rating Scale scores, and serum cortisol compared to placebo. Explore. https://doi.org/10.1016/j.explore.2024.103062

Chandrasekhar, K. et al. (2012) — Landmark double-blind, placebo-controlled RCT in chronically stressed adults. 300 mg KSM-66 twice daily for 60 days reduced cortisol by 14.5–27.9% and significantly improved stress and anxiety scores. Indian Journal of Psychological Medicine. https://doi.org/10.4103/0253-7176.106022

Salve, J. et al. (2019) — RCT in healthy adults under stress. 300 mg KSM-66 daily significantly reduced stress and anxiety scores versus placebo. Cureus. https://doi.org/10.7759/cureus.6466

Expert View

Dr. Peter Attia takes 600 mg Ashwagandha before bed as part of his sleep and recovery stack, primarily to manage cortisol and improve sleep quality during periods of high training or life stress (Peter Attia MD podcast, AMA episodes).

Dr. Andrew Huberman recommends 300–600 mg in the late afternoon or early evening (around 4–6 pm or before bed) to lower cortisol and reduce anxiety without blunting the natural morning cortisol rise needed for energy, focus, and motivation (Huberman Lab podcasts and AMAs).

Practical Dosage for Stress & Anxiety

  • Most common effective dose in studies: 300–600 mg per day (often split into two doses)
  • Best taken in the late afternoon or evening to align with natural cortisol rhythm
  • Many experts recommend cycling: 8–12 weeks on, followed by a 2–4 week break for long-term use

Safety & Notes

Ashwagandha is generally well tolerated at 300–600 mg/day for up to 12 weeks. Mild gastrointestinal upset can occur in some people. Not recommended during pregnancy, breastfeeding, or for individuals with autoimmune conditions (e.g. Hashimoto’s, rheumatoid arthritis) without medical supervision. May interact with thyroid medications and sedatives. Always consult your healthcare provider before use.

This is not medical advice. BioHackNZ provides general information based on published research. Always consult your healthcare provider before starting any supplement regimen. Individual results vary.

Last updated: 21 May 2026 | BioHackNZ Research Team

Shop Ashwagandha KSM-66 Root Extract
View Product →