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NCT Number: NCT07220447

L-Theanine to Support Relaxation and Mood for Cancer Patients in Surveillance

This clinical trial tests the feasibility, best dose, and effectiveness of L-theanine for supporting relaxation and mood among cancer patients in surveillance. L-theanine is a substance found in the leaves of green tea with potential to enhance mental health and well-being. It works by increasing certain chemicals within the body that have been associated with stress reduction, mood stabilization, and improved cognitive performance.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

City of Hope Medical Center, Duarte, California, United States

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About this study

PRIMARY OBJECTIVES:

I. To determine the feasibility of L-theanine use among cancer patients in surveillance based on adherence.

II. To determine the relationship of L-theanine on relaxation and supporting mood among cancer patients in surveillance with a dose of 200mg once daily versus (vs) twice daily, as measured by Visual Analog Scale-Relaxation (VAS-R).

SECONDARY OBJECTIVES:

I. To observe the relationship of L-theanine in reducing anxiety among cancer patients in surveillance, as measured by Visual Analog Scale-Anxiety (VAS-A).

II. To observe the relationship of L-theanine on mood states as measured by Short Form of the Profile of Mood States (POMS-SF).

EXPLORATORY OBJECTIVES:

I. To determine the feasibility of L-theanine use among cancer patients in surveillance based on recruitment.

II. To observe the relationship of L-theanine in supporting sleep among cancer patients in surveillance as measured by the Pittsburgh Sleep Quality Index (PSQI).

III. To describe the side effects of L-theanine supplementation. IV. To observe the relationship between L-theanine on symptom burden among cancer patients in surveillance as measured by Edmonton Symptom Assessment Scale (ESAS).

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM I: Patients receive L-theanine orally (PO) once daily (QD) for 6 weeks in the absence of unacceptable toxicity.

ARM II: Patients receive L-theanine PO twice daily (BID) for 6 weeks in the absence of unacceptable toxicity.

After completion of study intervention, patients are followed up at 14 days.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Documented informed consent of the participant and/or legally authorized representative.
  • Assent, when appropriate, will be obtained per institutional guidelines
  • Willingness to comply with all study interventions including the use of L-theanine and follow-up assessments
  • Age: ≥ 18 years
  • Ability to read and understand English or Spanish for questionnaires
  • Patients must be a cancer patient who has completed treatment and has been in surveillance for at least 6 months
  • Participants must not have used any herbs or supplements in the past 30 days
  • Participants must report an anxiety score of > 3 on Visual Analog Scale - Anxiety
  • Participants must not have had any changes to their psychiatric medications within the past 60 days
  • Women of childbearing potential (WOCBP): negative urine or serum pregnancy test. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required
  • Agreement by females and males of childbearing potential to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 1 month after the last dose of protocol therapy.
  • Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for > 1 year (women only)

Exclusion criteria

  • Concurrent use of other alternative medicines, including herbal agents and high-dose vitamins and minerals, unless taken to correct a documented vitamin or mineral insufficiency
  • Chemotherapy, radiation therapy, biological therapy, immunotherapy, or any other systemic treatment excluding hormonal therapy (must be on a stable dose of hormonal therapy for at least 60 days)
  • Any patients taking bortezomib, as L-theanine can decrease effectiveness
  • Any patients currently enrolled in other clinical trials that might interfere with the results of this study
  • History of allergic reactions attributed to compounds of similar chemical or biologic composition to study agent
  • Any patients with an ongoing active/unstable psychiatric condition, depressive/bi-polar related disorders, anxiety, psychosis disorders, or substance use that may interfere with the ability to participate in the study as outlined in the study procedures section of the protocol
  • Any patients with chronically unstable blood pressure or chronic low blood pressure
  • Diagnosis of Gilbert's disease
  • Females only: Pregnant or breastfeeding
  • Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures
  • Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)

Treatment and study plan

Survey Administration

Other

Ancillary studies

Theanine

Drug

Given L-theanine PO

Other names: L-theanine, N-Ethyl-L-Glutamine, Suntheanine, Theanin

Primary outcomes

  1. Adherence rates

    Time frame: Up to 8 weeks

    Will consider the study feasible if at least 75% of enrolled participants adhere to the planned intervention. Adherence will be defined as having at least 75% study drug accountability. Will be estimated along with the 95% exact binomial confidence interval.

  2. Perceived levels of relaxation

    Time frame: From baseline to day 42

    Measured via Visual Analog Scale-Relaxation (VAS-R). Response is defined as a favorable change of at least 1.5 points on the VAS-R. Will be estimated along with the 95% exact binomial confidence interval. Within-group mean changes in VAS-R will be examined using paired t-tests (comparing any two time points of interest).

Secondary outcomes

  1. Self-perceived anxiety

    Time frame: From screening to day 42

    Assessed via Visual Analog Scale-Anxiety. Within-group mean changes will be examined using paired t-tests (comparing any two time points of interest). Between-group mean changes will be evaluated at each time point using independent-samples t-tests.

  2. Anxiety and depression

    Time frame: From baseline to day 42

    Assessed via Hospital Anxiety and Depression Scale. Within-group mean changes will be examined using paired t-tests (comparing any two time points of interest). Between-group mean changes will be evaluated at each time point using independent-samples t-tests.

  3. Transient mood states

    Time frame: From baseline to day 42

    Assessed via Short Form of the Profile of Mood States that includes tension-anxiety, depression-dejection, anger-hostility, vigor-activity, fatigue-inertia, and confusion-bewilderment. Within-group mean changes will be examined using paired t-tests (comparing any two time points of interest). Between-group mean changes will be evaluated at each time point using independent-samples t-tests.

Sponsors and collaborators

Lead sponsor

City of Hope Medical Center

Other

Collaborators

  • National Cancer Institute (NCI)

Registry information

Official study title

Investigating the Feasibility and Relationship of L-Theanine in Supporting Relaxation and Mood in Cancer Patients in Surveillance

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Oct 24, 2025
Registry last updated
May 8, 2026

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.

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