Ashwagandha: What the Research Actually Shows

TL;DR
Ashwagandha is one of the most clinically validated adaptogens. Strong evidence supports its use for reducing stress, anxiety, and cortisol, and improving sleep quality. Emerging data also shows benefits for physical performance and recovery. Best taken in the evening. Evidence rating: ⭐⭐⭐⭐ Strong for stress/sleep; ⭐⭐⭐ Promising to Strong for performance.

What the Research Shows

A 2024 meta-analysis of 9 RCTs (558 participants) confirmed significant reductions in perceived stress, anxiety, and cortisol. A 2021 meta-analysis found clear benefits for sleep quality and latency. For physical performance, a 2021 Bayesian meta-analysis showed improvements in strength, muscle mass, and VO₂ max.

Expert Recommendations

Dr. Peter Attia takes 600 mg Ashwagandha before bed as part of his sleep cocktail (with Glycine and Magnesium L-Threonate) — AMA 42, Peter Attia MD.

Dr. Andrew Huberman recommends 300–600 mg in the late afternoon or evening to lower cortisol and support relaxation without blunting morning cortisol needed for energy (Huberman Lab podcasts and AMAs).

Practical Takeaways for New Zealanders

Given high stress levels and sleep challenges in modern life, Ashwagandha offers a well-researched, low-risk option for foundational support. Best used cyclically (8–12 weeks on, 2–4 weeks off) and timed in the evening.

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