Head-to-head evidence comparison — which supplement is right for you?
L-Theanine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
150-300mg kavalactones daily
Evening for relaxation, 30-60 minutes before stressful events, Before bed for sleep
Water-extracted root powder or capsules
100-200mg
Morning with coffee for focus, Evening for relaxation, As needed for stress
Suntheanine® capsules or powder
30-60 minutes
30-60 minutes
30-60 minutes
1-2 hours
30-60 minutes
30-60 minutes
30-60 minutes
Varies
Azapirones for generalized anxiety disorder
The Cochrane database of systematic reviews (2006) · Meta analysis · n=5908
The calculated number needed to treat for azapirones using the Clinical Global Impression scale was 4.4 (95% confidence interval (CI) 2.16 to 15.4).
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.
The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis
Sleep medicine reviews (2025) · Meta analysis · n=897
The findings indicate the potential use of L-theanine in the management of sleep disturbances; however, the lack of studies on "pure" L-theanine warrants further investigation.
Efficiency of Different Supplements in Alleviating Symptoms of ADHD with or Without the Use of Stimulants: A Systematic Review
Nutrients (2025) · Systematic review
The evidence revealed the potential use of supplements as complementary ADHD treatments under clinical guidance.
The Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review
International journal of molecular sciences (2023) · Systematic review
Although good sleep quality in children has been proven to be a key factor for optimal cognitive, physical and psychological development, a significant and ever-increasing percentage of the pediatric population suffers from sleep disorders.
L-Theanine has a higher evidence score (9/10 vs 9/10) and wins in 2 of 3 categories.
For reduce anxiety & stress, Kava has a higher relevance score (90 vs 85).
No known interactions between Kava and L-Theanine have been documented in our database. However, always consult a healthcare provider before combining supplements.