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Head-to-head evidence comparison — which supplement is right for you?
Ashwagandha wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
10 of 10 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
4 of 7 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (3)
Outcomes where both Ashwagandha and Kava have evidence — compare verdict strength side-by-side.
300-600mg daily (standardized extract)
Morning for daytime stress, Evening for sleep support
KSM-66 or Sensoril standardized extract
150-300mg kavalactones daily
Evening for relaxation, 30-60 minutes before stressful events, Before bed for sleep
Water-extracted root powder or capsules
2-4 weeks
2-4 weeks
2-4 weeks
First week
30-60 minutes
30-60 minutes
30-60 minutes
1-2 hours
Effects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis
Journal of the American Nutrition Association (2024) · Meta analysis · n=873
Significant reduction in HAM-A anxiety scores (p=0.0007)
Effects of Withania somnifera Extract in Chronically Stressed Adults: A Randomized Controlled Trial
Nutrients (2024) · Rct · n=131
Our findings demonstrate the stress-reduction capabilities of this well-characterized aqueous extract of WS (root and leaf) at the low dose of 125 mg/day, in a dose-dependent manner, via the modulation of the HPA axis.
Plant-derived nootropics and human cognition: A systematic review
Critical reviews in food science and nutrition (2023) · Systematic review
Bacopa monnieri improves language, learning and memory.
Herbal medicines in the treatment of psychiatric disorders: 10-year updated review
Phytotherapy research : PTR (2018) · Systematic review
Other encouraging herbal medicines with preliminary evidence include Curcuma longa (turmeric) in depression, Withania somnifera (ashwagandha) in affective disorders, and Ginkgo biloba (ginkgo) as an adjunctive treatment in Schizophrenia.
GABA-modulating phytomedicines for anxiety: A systematic review of preclinical and clinical evidence
Phytotherapy research : PTR (2018) · Systematic review
An open-ended search to 5 July 2017 was conducted using MEDLINE (PubMed), Scopus, and Cochrane library online databases and performed in a stepped format from preclinical to clinical investigations.
Herbal medicine for insomnia: A systematic review and meta-analysis
Sleep medicine reviews (2015) · Meta analysis · n=1602
There was no statistically significant difference between any herbal medicine and placebo, or any herbal medicine and active control, for any of the thirteen measures of clinical efficacy.
Based on meta-analysis showing significant HAM-A score reduction (p=0.0007) and RCT evidence at 125mg dose. High heterogeneity (I2=98%) in pooled analysis suggests variable response. Extract standardization affects bioavailability.
Based on multiple meta-analyses showing efficacy vs placebo with effect size comparable to benzodiazepines for mild-moderate anxiety. WS1490 extract showed OR=3.3 vs placebo. Effectiveness limited to 60% due to mixed results in some GAD populations and study quality limitations.
AI-estimated from published studies. Interpret as directional guidance.
Ashwagandha has a higher evidence score (7.5/10 vs 9/10) and wins in 2 of 3 categories.
For reduce anxiety & stress, Ashwagandha has a higher relevance score (95 vs 90).
No known interactions between Ashwagandha and Kava have been documented in our database. However, always consult a healthcare provider before combining supplements.