Acute Effects of L-Theanine and L-Tyrosine on Cognitive and Archery Performance (THEA-TYR)

November 7, 2026 updated by: Halil UÇAR

Acute Effects of L-Theanine, L-Tyrosine, and Combined Supplementation on Cognitive and Archery Performance: A Randomized, Placebo-Controlled Crossover Study

This study aims to investigate the acute effects of L-theanine, L-tyrosine, and their combination on cognitive performance and archery performance in trained archers. The study will use a randomized, placebo-controlled, five-condition crossover design involving 21 healthy male archers aged 18 years or older.

Participants will complete five experimental conditions: placebo, L-theanine supplementation (6 mg/kg), L-tyrosine supplementation (50 mg/kg), combined L-theanine and L-tyrosine supplementation, and a no-supplement control condition. Supplements will be administered 60 minutes before performance assessments, with at least 72 hours between experimental sessions.

Cognitive performance will be assessed using the Stroop Test, while archery performance will be evaluated through indoor target shooting at 18 meters. Mood states and perceived exertion will also be assessed using the BRUMS questionnaire and Borg CR-10 scale, respectively.

The study will examine whether these supplementation conditions produce different acute responses in cognitive function and archery performance.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
21

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • 1. Being 18 years of age or older. 2. Being a healthy male individual. 3. Having at least five years of regular archery experience. 4. Training in archery at least three days per week. 5. Having national or international competition experience in archery. 6. Voluntarily agreeing to participate in the study.

Exclusion Criteria:

  • 1. Having a medical condition that may interfere with participation in the study.

    2. Having a known allergy or hypersensitivity to L-theanine or L-tyrosine. 3. Using medications or supplements that may affect cognitive or physical performance during the study period.

    4. Being unable to complete all five experimental sessions. 5. Failing to comply with the study procedures.

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Five-Condition Crossover Group

All participants will complete five experimental conditions in a randomized crossover design: placebo, L-theanine, L-tyrosine, combined L-theanine and L-tyrosine, and no-supplement control. Each participant will receive all five conditions, with at least 72 hours of washout between sessions.
Drug: Placebo

Participants will receive a placebo 60 minutes before performance assessments. The placebo will be prepared in a form identical to the active supplementation capsules to maintain blinding.

Drug: L-Theanine

Participants will receive L-theanine at a dose of 6 mg/kg body weight, administered 60 minutes before performance assessments.

Drug: L-Tyrosine

Participants will receive L-tyrosine at a dose of 50 mg/kg body weight, administered 60 minutes before performance assessments.

Drug: L-Theanine + L-Tyrosine

Participants will receive a combination of L-theanine (6 mg/kg body weight) and L-tyrosine (50 mg/kg body weight), administered together 60 minutes before performance assessments.

Other: No-Supplement Control

Participants will complete the performance assessments without receiving any supplementation during this condition. This condition will serve as the no-supplement control for comparison with the placebo and active supplementation conditions.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Total Archery Shooting Score
Time Frame: Immediately after the archery shooting task in each experimental session (approximately 60 minutes after supplement or placebo administration).

Archery performance will be assessed by recording the total score obtained from 15 arrows (5 sets of 3 arrows) shot at an indoor target from a distance of 18 meters using a 40-cm target face. Higher scores indicate better archery performance.
Immediately after the archery shooting task in each experimental session (approximately 60 minutes after supplement or placebo administration).

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Halil UÇAR

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 7, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 7, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 12, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • INU-ARCH-2026-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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