Useful Sleep Aid- l-Theanine

Treating Insomnia with Theanine

Theanine  (l-theanine) is an amino acid found in tea leaves.  In addition to providing benefits as an anti-oxidant, theanine is useful in sleep induction, as well.

L-Theanine provides an interesting combination of salutary benefits.  It acts as a non-sedating relaxant by enhancing alpha wave production in the brain. It improves mental focus during wakeful hours, yet it enhances sleep quality.  The alpha-wave enhancing effect is very useful for students, promoting concentration, yet it does not cause sleep disturbances that result from the use of caffeine and amphetamines. The effective dosage range of L-Theanine ranges between 50 and 200 mg, or more, per day.

While 3 or 4 cups of tea would be expected to contain 100-200mg of l-theanine, this same volume of tea contains a great deal of caffeine.  The caffeine itself will improve concentration, but headache can occur as the caffeine wears off, and sleep disorders are common with caffeine ingestion. Decaffeinated tea would be a good choice, but the decaffeinating process destroys the L-theanine.

After ingestion of capsular or tablet forms of l-theanine, blood levels will  reach maximum peak blood levels in about 30 mins, and peak  in 2-4 hours. For maximal effect, it is best taken in the morning to enhance concentration, and immediately before bed to enhance sleep.

I have my patients use one of our Green Tea Extract Capsules at bed time, combined with a melatonin 3 mg tablet.  This is a very gentle approach to sleep induction, and it is a good place to start. If needed, the melatonin can be increased to 9 mg. 


In patients with anxiety and/or depression, the addition of 5-HTP can be added.   We use a product that is called “Snokker™,” which combines the 5-HTP and l-theanine in an affordable, single tablet. Adding melatonin to the Snokker™ makes it very, very potent as a sleep inducer. 


Recommended Products:



  1. Green Tea Extract Capsules 400 mg #100 per bottle. ($11.95)
  2. Snokker™ 200 mg L-theanine, 200 mg 5-HTP #30 per bottle. ($29.95)
  3. Melatonin 3 mg #90 per bottle. ($16.79)
About David S Klein, MD 149 Articles
David S. Klein, MD, FACA, FACPM was born in Washington, DC, and was raised in Chevy Chase, Maryland. He completed his undergraduate education at the University of Maryland with degrees in Chemistry and Psychology. Medical School was completed at the University of Maryland at Baltimore, followed by Internship in General Surgery at the University of North Carolina and Residency in Anesthesiology at the Duke University, Durham, North Carolina. Dr Klein has been practicing medicine since 1983, concentrating in Pain Medicine, Minimally Invasive Medicine and Surgery, and Neuroendocrinology. Earning Board Certification in Anesthesiology, Dr. Klein was elected Fellow in the American College of Anesthesiology, and he was elected Fellow in the American College of Pain Medicine. He is currently an adjunct Associate Professor at the University of Central Florida, School of Medicine. He has focused his private practice on treating patients with hormone imbalance issues, nutritional deficiency related medical problems as well as pain related issues and impairment. With a highly-complex, CLIA licensed laboratory in-house, he has been able to provide rapid-turn around analysis efficiently and cost-effectively. Lecturing extensively nationally as well as internationally, Dr. Klein has authored many articles on topics relating to pain, injury and nutritionally modulated illness. His radio show, “Pain Free Living,” received top ratings during the 6 years it was on the air. Currently practicing in Longwood, Florida, Dr. Klein practices entirely in the office setting.