Ashwagandha Science ashwagandhascience.org

Research summary

Ashwagandha and Cognition

Key takeaway

The cited trials studied different populations and preparations. A small trial in mild cognitive impairment reported favorable test results, while most cognitive tests and overall mood in a healthy-adult trial did not differ significantly from placebo over time.[1], [2]

What these findings do not establish

Based on a single small pilot trial of 50 adults with mild cognitive impairment using 300 mg twice daily for 8 weeks; the findings need confirmation in larger trials and may not apply to healthy adults.[1]

Based on one trial with 59 participants analyzed, using 225 mg per day of a liposomal root-and-leaf extract for 30 days; improvements within a treatment group do not establish superiority over placebo. The selected positive comparisons need replication and do not establish a general memory, attention, or mood benefit.[2]

What the two trials measured

In a small randomized, double-blind, placebo-controlled trial of adults with mild cognitive impairment, ashwagandha root extract significantly improved measures of immediate and general memory, attention, and information-processing speed compared with placebo. Based on a single small pilot trial of 50 adults with mild cognitive impairment using 300 mg twice daily for 8 weeks; the findings need confirmation in larger trials and may not apply to healthy adults.[1]

In a randomized, double-blind, placebo-controlled trial of healthy young adults, most cognitive tests and overall mood showed no significant differences in change over time between liposomal ashwagandha and placebo. Selected comparisons favored ashwagandha for picture-recognition reaction time after the first dose and fatigue before dosing on day 30. Based on one trial with 59 participants analyzed, using 225 mg per day of a liposomal root-and-leaf extract for 30 days; improvements within a treatment group do not establish superiority over placebo. The selected positive comparisons need replication and do not establish a general memory, attention, or mood benefit.[2]

Safety and medication context

NCCIH does not recommend ashwagandha for people with thyroid or autoimmune disorders or those who are about to have surgery. Discuss these conditions and any planned surgery with your healthcare professional before considering ashwagandha; supplement research does not justify changing prescribed care.[3]

Ashwagandha may interact with medicines for diabetes or high blood pressure, immunosuppressants, sedatives, anticonvulsants, and thyroid hormone medicines. Discuss possible interactions with your prescriber or pharmacist before use; do not stop, replace, or adjust prescribed medicines based on supplement information.[3]

References

  1. Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions.. Journal of dietary supplements. 2017. Randomized controlled trial View source →
  2. Acute and Repeated Ashwagandha Supplementation Improves Markers of Cognitive Function and Mood.. Nutrients. 2024. Randomized controlled trial View source →
  3. Ashwagandha: Usefulness and Safety. NIH National Center for Complementary and Integrative Health. Retrieved 2026-09-30. Government health fact sheet View source →

Read the concise FAQ answer

Use the FAQ when you want the direct answer first, then return here for the full evidence context.

Does ashwagandha improve memory and focus?

The evidence is mixed and population-specific. A small mild-cognitive-impairment trial reported improvements, while most cognitive tests in a healthy-young-adult trial did not differ from placebo.

Read FAQ →

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