The Effect of the Amino Acid L-Theanine on Alertness and Vigilance

December 5, 2023 updated by: David Bauer, The University of Texas Health Science Center, Houston
The amino acid l-theanine (the active ingredient in green tea) is considered to have a calming effect without causing sleepiness. This study evaluates whether l-theanine affects blood pressure, heart rate, alertness, and sense of well-being.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

26

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Sugar Land, Texas, United States, 77478
        • Physicians at Sugar Creek

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • adult
  • able to swallow capsule

Exclusion Criteria:

  • none

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo capsule
Dietary supplement: Placebo capsule
Experimental: L-theanine capsule
Dietary supplement: L-theanine capsule
L-theanine 250mg capsule

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Alertness
Time Frame: 48 hrs
The average response time to identify a small rectangle shown on a computer screen.
48 hrs
Alertness
Time Frame: 48 hrs
Degree of subjective alertness, measured on a visual analog scale
48 hrs
Well-Being
Time Frame: 48 hrs
Sense of subjective well-being as measured on a visual analog scale
48 hrs

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

The University of Texas Health Science Center, Houston

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2011

Primary Completion (Actual)

October 1, 2012

Study Completion (Actual)

October 1, 2012

Study Registration Dates

First Submitted

May 3, 2013

First Submitted That Met QC Criteria

May 7, 2013

First Posted (Estimated)

May 10, 2013

Study Record Updates

Last Update Posted (Estimated)

December 13, 2023

Last Update Submitted That Met QC Criteria

December 5, 2023

Last Verified

December 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • HSC-GEN-11-0299

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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