L-Theanine for Sleep

An amino acid from green tea that promotes relaxation without sedation.

Also known as: Theanine • Suntheanine

other Names
Gamma-ethylamino-L-glutamic acid
primary Benefits
Promotes relaxation, reduces stress, improves sleep quality.
common Dose
100-200 mg
best Form
Suntheanine (patented, pure L-isomer form)
timing
30-60 minutes before bedtime
safety Rating
Very safe, non-sedating, and low risk of side effects.

Overview

L-Theanine is an amino acid found primarily in green and black tea. It is known for its unique ability to promote a state of calm alertness. For sleep, it helps to quiet the mind, reduce anxiety, and improve sleep quality by increasing alpha brain waves, which are associated with a state of wakeful relaxation.

Key Benefits

Promotes Relaxation

Increases alpha brain waves, leading to a state of calm focus and reduced mental chatter.

Improves Sleep Onset and Quality

Helps individuals fall asleep more easily and experience deeper, more restorative sleep.

Reduces Stress and Anxiety

Can lower levels of stress hormones like cortisol and increase calming neurotransmitters like GABA and serotonin.

Dosage & How to Take

100-200 mg per day.

PurposeDoseNotes
Sleep and Relaxation200 mgTaken before bed.
Daytime Calm100-200 mgCan be taken as needed during the day.

Best Time to Take

For sleep, take 30-60 minutes before bed. For daytime anxiety, take as needed.

With or Without Food

Can be taken with or without food.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Capsules/TabletsHighConvenience and accurate dosing.Look for pure L-Theanine or Suntheanine.
PowderHighCost-effective and can be added to beverages.Has a mild, slightly savory taste.

Side Effects & Safety

Common

  • Extremely rare, generally considered very safe.

Rare

  • Headaches or dizziness in sensitive individuals.

Contraindications

  • None well-documented, but consult a doctor if taking blood pressure medication.

Interactions

Stimulants (e.g., caffeine)Beneficial

L-Theanine can smooth out the jittery effects of caffeine, creating a state of calm focus.

Blood pressure medicationMinor

May have an additive effect, potentially lowering blood pressure too much.

Scientific Research

2016https://www.tandfonline.com/doi/full/10.1080/1028415X.2017.1390434

L-theanine as a functional food additive: Its role in mood and cognitive function

L-theanine has been shown to promote relaxation by increasing alpha brain wave activity, which is indicative of a state of wakeful rest.

Food Sources

Green tea
Black tea
Bay bolete mushrooms

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.