Theanine, (L)-IsomerNCT01851122
The Effect of the Amino Acid L-Theanine on Alertness and Vigilance
A study testing L-theanine capsule in people with Theanine, (L)-Isomer, run by The University of Texas Health Science Center, Houston at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Theanine, (L)-Isomer
- What is being tested?
- L-theanine capsule
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 26 participants
- Where
- 1 siteUnited States
- Study dates
- Nov 2011to Oct 2012
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- adult
- able to swallow capsule
Who cannot join
- none
Trial locations and contacts
1 site in 1 country.
About this study
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.
- Conditions
- Theanine, (L)-Isomer
- Being tested
- L-theanine capsule, Placebo capsule
- Keywords
- l-theanine, alertness, well-being
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
L-theanine capsuleDietary supplement
L-theanine 250mg capsule
Placebo capsuleDietary supplement
| Study group | Role | What they receive |
|---|---|---|
| Placebo capsule | Placebo comparator | Not described Receives: Dietary Supplement: Placebo capsule |
| L-theanine capsule | Experimental | Not described Receives: Dietary Supplement: L-theanine capsule |
What is being measured
The primary outcome is the main question the study is designed to answer.
Alertness
The average response time to identify a small rectangle shown on a computer screen.
Measured: 48 hrs
Alertness
Degree of subjective alertness, measured on a visual analog scale
Measured: 48 hrs
Well-Being
Sense of subjective well-being as measured on a visual analog scale
Measured: 48 hrs
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2013 (estimated)
- Study startNov 2011
- Primary completionOct 2012
- Study completionOct 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Theanine, (L)-IsomerStudies of the same condition, open and under way.
- More trials run by The University of Texas Health Science Center, HoustonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Bauer, The University of Texas Health Science Center, Houston
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01851122
- Sponsor's protocol ID
- HSC-GEN-11-0299
- Status last verified
- Dec 2023
- First submitted
- 3 May 2013
- Last updated
- 13 Dec 2023
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 13 Dec 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of the Amino Acid L-Theanine on Alertness and Vigilance
- ClinicalTrials.gov ID
- NCT01851122
- Acronym / sponsor ID
- HSC-GEN-11-0299
- Conditions
- Theanine, (L)-Isomer
- Keywords
- l-theanine, alertness, well-being
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- The University of Texas Health Science Center, HoustonUniversity, hospital or other
- Study start
- Nov 2011
- Primary completion
- Oct 2012 (actual)
- Study completion
- Oct 2012 (actual)
- First posted
- 10 May 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Placebo capsule | Placebo comparator | Dietary Supplement: Placebo capsule |
| L-theanine capsule | Experimental | Dietary Supplement: L-theanine capsule |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- adult
- able to swallow capsule
Key exclusion criteria (1 listed)
- none
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| L-theanine capsuleL-theanine 250mg capsule | Dietary supplement | L-theanine capsule |
| Placebo capsule | Dietary supplement | Placebo capsule |
Primary outcome
Alertness
Time frame: 48 hrs
The average response time to identify a small rectangle shown on a computer screen.
Alertness
Time frame: 48 hrs
Degree of subjective alertness, measured on a visual analog scale
Well-Being
Time frame: 48 hrs
Sense of subjective well-being as measured on a visual analog scale
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Dec 2023.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing L-theanine capsule in people with Theanine, (L)-Isomer, run by The University of Texas Health Science Center, Houston at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Dec 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Alertness (time frame: 48 hrs). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Dec 2023.