L-Theanine is an amino acid that helps promote a restful, relaxed state without diminishing daytime alertness.*


Human studies have found that supplemental L-theanine promotes the generation of alpha brain waves, suggesting a state of relaxation.* Controlled clinical trials have shown that L-theanine can support a healthy stress response.*


L-Theanine Directions and/or Dosage

Adults, take 1 capsule up to three times daily. For maximum support, take 2 capsules three times daily, or as recommended by your healthcare professional.


If you are pregnant, nursing, or taking prescription drugs, consult your healthcare professional prior to use.Keep out of reach of children.Keep bottle tightly closed. Store at room temperature. Avoid excessive heat and direct sunlight.


Patient Support

There is no Patient Support information available for this product


  • A. L-theanine is an amino acid present in small quantities in black, oolong, and green teas. Research shows that L-theanine can help promote a restful, relaxed state without diminishing daytime alertness.* The L-theanine used in Enzymatic Therapy’s product is Suntheanine®, a patented form of L-theanine, that is a trademark of Taiyo International, Inc. Suntheanine is produced using an enzymatic method.

  • A. The effect of L-theanine on brain levels of serotonin in humans is still unclear. Animal studies completed to date have provided conflicting data. Until more research is completed, we recommend that persons taking antidepressant medications consult their healthcare practitioner before using L-theanine.

  • A. Caution should be taken whenever recommending, or consuming, nutritional supplements. Healthcare professionals can use this drug-nutrient interaction checker to view potential interactions with the ingredients of L-Theanine. Patients should consult their preferred healthcare professional for any supplement questions.

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Drug-Nutrient Interactions


Drug-Nutrient Interactions

Use this reference tool to identify potential interactions between prescription drugs and nutrients.

Check for Interactions