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OpenTrials
Completed

NCT Number: NCT01851122

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

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.

Completed

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Key information

Conditions

Theanine, (L)-Isomer

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Physicians at Sugar Creek

Sugar Land, Texas, 77478, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • adult
  • able to swallow capsule

Exclusion criteria

  • none

Treatment and study plan

L-theanine capsule

Dietary Supplement

L-theanine 250mg capsule

placebo capsule

Dietary Supplement

Primary outcomes

  1. Alertness

    Time frame: 48 hrs

    The average response time to identify a small rectangle shown on a computer screen.

  2. Alertness

    Time frame: 48 hrs

    Degree of subjective alertness, measured on a visual analog scale

  3. Well-Being

    Time frame: 48 hrs

    Sense of subjective well-being as measured on a visual analog scale

Sponsors and collaborators

Lead sponsor

The University of Texas Health Science Center, Houston

Other

Registry information

Important dates

Study start
2011
Primary completion
2012
Study completion
2012
First posted
May 10, 2013
Registry last updated
Dec 13, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.