L-Theanine for Insomnia
A StrongBased on 16 studies (4 meta-analyses, 4 RCTs) with 916 total participants. 11/16 studies show positive effects.
Key Statistics
16
Studies
916
Participants
Positive
Grade
Referenced Papers
Dosage & Usage
Commonly Used Dosages
- sleep:
- 200-400 mg, 30-60 min before bed
Upper limit: Not established; generally safe up to 900 mg/day
Dosages Studied in Research
| Dosage | Duration | Effect | N |
|---|---|---|---|
| L-theanine 50-900 mg/day; effective range 200-450 mg/day | -- | Positive | 550 |
| None | 8 weeks | Positive | 40 |
| Melatonin 3 mg or L-theanine 200 mg taken 2h before bedtime for 14 days | 2 weeks | Positive | 120 |
| varies by supplement | -- | Positive | -- |
| 7 L fermentation product; GABA 12.555 µmol/L, L-theanine 0.471 mg/mL | -- | Positive | -- |
| l-theanine 200 mg/day, GABA 111.1 mg/day, AVLE 50 mg/day, l-serine 300 mg/day | -- | Positive | 160 |
| None | -- | Positive | -- |
| iron, 5-hydroxytryptophan (5-HTP), theanine, antihistamines (OTC supplements) | -- | Mixed | -- |
Best taken: 30-60 minutes before bed
Safety & Side Effects
Reported Side Effects
- ⚠ Headache
- ⚠ Dizziness
- ⚠ GI discomfort
Known Interactions
- ● Blood pressure medications — L-theanine may lower blood pressure
- ● Stimulants (caffeine) — may partially counteract stimulant effects
- ● Sedatives — potential additive calming effects
Tolerable upper intake: Not established; generally safe up to 900 mg/day
Always consult your healthcare provider before starting any supplement.
Frequently Asked Questions
Does L-Theanine help with Insomnia?
How much L-Theanine should I take for Insomnia?
Are there side effects of L-Theanine?
How strong is the evidence for L-Theanine and Insomnia?
Related Evidence
Other ingredients for Insomnia
L-Theanine for other conditions
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.