"L-Theanine As A Natural Anxiolytic: A Review Of Its Neurophysiological Mechanisms, Clinical Efficacy, And Safety In Anxiety And Stress Management"

Abstract

This review aims to explore the current evidence on the prevalence, neurobiological mechanisms, and treatment options for anxiety disorders, with a specific focus on L-theanine – a naturally occurring amino acid found in green tea – as a potential safe and effective complementary therapy.

Materials and methods: Review of the studies available on open access sources at National Library of Medicine, PubMed and Google Scholar.

Results: Anxiety disorders are among the most prevalent psychiatric conditions worldwide and are frequently associated with impaired quality of life and high comorbidity rates. While pharmacological treatments remain the standard, they often have limitations, including side effects and inadequate efficacy. L-theanine has shown promise in modulating neurotransmitters such as GABA, serotonin, and dopamine, enhancing alpha brain wave activity, and regulating the hypothalamic–pituitary–adrenal (HPA) axis. Clinical trials and systematic reviews indicate that L-theanine supplementation (typically at doses of 200-400 mg/day) can reduce subjective stress, anxiety symptoms, and improve sleep and cognitive function in both healthy individuals and patients with anxiety-related disorders. Notably, its favorable safety profile and low risk of adverse effects make it an attractive non-pharmacologic option.

Conclusion: L-theanine appears to be a promising adjunctive intervention for managing anxiety and stress, especially in individuals seeking natural alternatives or experiencing side effects from conventional therapies. It may be particularly beneficial for those with mild to moderate symptoms or subclinical stress. While evidence supports its short-term use, further high-quality, long-term studies are needed to determine its clinical efficacy, safety, and optimal dosing strategies. Until then, L-theanine should be considered a complementary, not primary, treatment and used under appropriate clinical guidance.