What is the recommended dosage for L-Theanine?

Sleep: 200-400 mg, 30-60 min before bed

What are the side effects of L-Theanine?

Potential side effects include: Headache, Dizziness, GI discomfort.

SleepCited

L-Theanine

amino_acid

Also known as: Gamma-glutamylethylamide, Suntheanine

About

L-Theanine is an amino acid found primarily in tea leaves that promotes relaxation without drowsiness. Research suggests it may support sleep quality by increasing alpha brain wave activity and modulating calming neurotransmitters like GABA and serotonin.

How It Works

Crosses BBB and increases alpha brain wave activity; boosts GABA, serotonin, and dopamine without sedation.

Evidence For Conditions

Condition	Grade	Studies	Participants
Insomnia	A Strong	16	916	Göster →
Sleep Onset Difficulty	A Strong	4	590	Göster →
Anxiety-Related Sleep Problems	B Moderate	2	--	Göster →

Side Effects

Headache
Dizziness
GI discomfort

Drug & Supplement Interactions

Blood pressure medications — L-theanine may lower blood pressure
Stimulants (caffeine) — may partially counteract stimulant effects
Sedatives — potential additive calming effects

Always inform your healthcare provider about all supplements you take.

Related Ingredients

5-HTP GABA Glycine Tryptophan

Quick Facts

Dosage: Sleep: 200-400 mg, 30-60 min before bed
Forms: capsule tablet powder
Natural Sources: Green tea, Black tea, Some mushrooms
Upper Limit: Not established; generally safe up to 900 mg/day
Best Time: 30-60 minutes before bed

Evidence Summary

Insomnia A Strong

Sleep Onset Difficulty A Strong

Anxiety-Related Sleep Problems B Moderate

FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure, or prevent any disease. The evidence grades presented are based on our analysis of published peer-reviewed research and do not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.