3 registrations that name L-theanine as a study arm and are recruiting or about to, as ClinicalTrials.gov listed them on Oct 20, 2026. Read each listing for its full criteria and current status.
Kymata never assesses eligibility. Each listing names its own criteria; only its study team can say whether someone can join. Trial doses are given under the trial's monitoring and are not a schedule for anyone outside it.
Filter 3 registrations
Status
Phase
4US sites across 1 state
1
2 to 4
5 to 19
20 or more
All 3 registrations
RecruitingNCT07220447
L-Theanine to Support Relaxation and Mood for Cancer Patients in Surveillance
Early phase 1
City of Hope Medical Center
About 50 people
Started Apr 21, 2026
In plain words An early phase 1 study of L-theanine in people 18 and older, run by City of Hope Medical Center. It plans to enroll about 50 people at 4 US sites.
Who it lists and where
Who the trial lists, as registered
Lists people 18 and older. Conditions: Hematopoietic and Lymphatic System Neoplasm; Malignant Solid Neoplasm.
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
8 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Survey Administration; Theanine
Registered summary
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.
Where, as registered
4 US sites in 1 state.
RecruitingNCT07135232
The Effects of Resistance Training and a Plant-Based Supplement on Perimenopausal Symptoms and Muscle Health.
No phase
Leeds Beckett University
About 72 people
Starts Mar 1, 2026 (estimated)
In plain words A study of L-theanine in female participants 40 to 55, run by Leeds Beckett University. It plans to enroll about 72 people at 1 site, none in the US.
Not currently engaging in consistent structured resistance training (defined as >3 resistance training sessions per week for 4 consecutive weeks, in the past six months).
Not on any HRT or hormonal contraception for at least one year before initiation of the study.
Able to attend laboratory visits and commit to the intervention schedule for 6 months.
4 more inclusion criteria and the exclusion criteria are on the listing.
The aim of this clinical trial is to determine if resistance training and a newly developed plant-based nutritional supplement can improve the symptoms and musculoskeletal health of perimenopausal women. The main questions it aims to evaluate are: 1. Can resistance training and the nutritional supplement - both independently and in combination - improve perimenopausal symptoms (e.g. cognition, mood, sleep) and musculoskeletal outcomes (e.g. strength, muscle mass)? 2. The full summary is on the listing.
Where, as registered
No US site; United Kingdom (1).
Not yet recruitingNCT07475299
Synbiotic Supplement With Botanical Extracts for Gut Microbiota Balance in Irritable Bowel Syndrome
No phase
Iuliu Hatieganu University of Medicine and Pharmacy
About 8 people
Starts Apr 2026 (estimated)
In plain words A study of L-theanine in people 18 to 70, run by Iuliu Hatieganu University of Medicine and Pharmacy. It plans to enroll about 8 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 70. Conditions: Irritable Bowel Syndrome (IBS).
Adults aged ≥18 years
Clinically confirmed diagnosis of Irritable Bowel Syndrome documented in the medical record
Presence of recurrent gastrointestinal symptoms such as bloating, abdominal discomfort, gas, or bowel habit disturbances (constipation, diarrhea, or mixed pattern) considered clinically relevant by the participant
Ability to understand the study procedures and provide written informed consent
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Synbiotic supplement containing probiotic strains, botanical extracts, magnesium, vitamin B1, and L-theanine designed to support gut microbiota balance.
Registered summary
The goal of this clinical trial is to evaluate whether a synbiotic dietary supplement containing botanical extracts and multiple probiotic strains can improve gastrointestinal symptoms and modulate gut microbiota composition in adults diagnosed with Irritable Bowel Syndrome (IBS). The full summary is on the listing.