longevitywatch
Evidence answer · Interventions

How much ashwagandha do you need per day?

Yes · Moderate evidence

For stress reduction, 240 to 500 mg per day already appears to have an effect; for safety, 600 mg per day has been studied for up to 8 weeks. The studies involved are relatively small, so consult your doctor if you are unsure or are taking medication.

The doses studied range from 240 to 600 mg per day, depending on what you want to achieve. For stress reduction and lower cortisol levels, 240 mg per day was already sufficient in a double-blind study lasting 60 days in healthy, stressed adults. Anxiety scores and morning cortisol fell in a statistically significant way, and no side effects were reported.

For sleep quality and milder symptoms of anxiety and depression, 500 mg per day emerges as a studied dose. After 90 days, anxiety and depression scores improved considerably. This study was partly funded by a party with a commercial interest, which makes the results somewhat less independent.

For improvements in memory and cognition in people with mild memory problems, 250 mg per day was investigated in a small pilot study (40 participants). The improvements were notably large, but these are early results that need to be confirmed by larger studies.

Safety at 600 mg per day has been studied in 80 healthy adults over 8 weeks. Blood markers, liver function and thyroid hormones remained normal, and no side effects were reported. Little is known about higher doses or use beyond 8 to 12 weeks, so caution is warranted. The finding that 600 mg can influence thyroid hormone levels in people with an underactive thyroid is preliminary and comes from a single small study. If you have a thyroid condition or take medication, discuss ashwagandha with your doctor first.

The evidence
5 studies · ≈ 330 participants

Based on 5 RCTs and pilot studies with 40-80 participants per study. No meta-analyses available in this source selection. One study has a commercial interest (PMID 37878284). Dose range: 240-600 mg/day, duration: 60-90 days.

Last updated: July 2026
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