4 registrations that name L-tryptophan 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 4 registrations
Status
All 4 registrations
RecruitingNCT05576038
Tryptophan for Impaired AhR Signaling in Celiac Disease
No phase
McMaster University
About 50 people
Started Dec 1, 2022
In plain words A study of L-tryptophan in people 18 to 75, run by McMaster University. It plans to enroll about 50 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 75. Conditions: Tryptophan Metabolism Alterations; Celiac Disease.
18 and 75 years of age
Celiac disease (CeD) diagnosis: Individuals with histological and serological evidence of CeD serology (positive biopsy and anti-tTG IgA)
Persistent CeD related symptoms (>40 on the Celiac Symptom Index) despite >1 year of a gluten free diet (GFD)
The exclusion criteria are on the listing.
What it tests, as registered
L-Tryptophan; Freedom SimpleCap Powder
Registered summary
This is a prospective, randomized, double-blind, placebo-controlled exploratory trial to evaluate the effect of L-tryptophan supplementation on celiac-related symptoms in individuals who have biopsy-confirmed celiac disease (CeD) and symptoms non-responsive to a gluten-free diet (GFD). Fifty participants, aged 18 to 75 years, who self-report persistent CeD-related symptoms despite taking a GFD for more than 1 year and who score \> 40 on the Celiac Symptom Index (CSI) will be randomized to receive L-tryptophan or placebo for 3 weeks.
Where, as registered
No US site; Canada (1).
RecruitingNCT06283706
The Tryptophan Requirement in Healthy Adults
No phase
The Hospital for Sick Children
About 40 people
Started Jun 1, 2024
In plain words A study of L-tryptophan in people 60 to 90, run by The Hospital for Sick Children. It plans to enroll about 40 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 60 to 90; healthy volunteers accepted. Conditions: Healthy Aging.
Consent provided.
Aged 60 to 90 years old.
In good general health as evidenced by medical history, physical health and blood draw.
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Tryptophan
Registered summary
The aging population is growing rapidly. For the first time ever, Canadian seniors outnumbered young adults in 2016. Aging is associated with many physical and metabolic deteriorations including the loss of muscle mass and strength, insulin resistance, increased inflammation and oxidative stress. The muscles of our bodies are composed of proteins and proteins are made of small building blocks called amino acids. Our bodies have the ability to make some amino acids which are called the non-essential amino acids. The full summary is on the listing.
Where, as registered
No US site; Canada (1).
Not yet recruitingNCT06861140
Exploring the Influence of Trptophan on the Treatment of Pouchitis
No phase
Universitätsklinikum Hamburg-Eppendorf
About 20 people
Starts Apr 1, 2025 (estimated)
In plain words A study of L-tryptophan in people 18 and older, run by Universitätsklinikum Hamburg-Eppendorf. It plans to enroll about 20 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists people 18 and older. Conditions: Pouchitis.
Pouchitis (PDAI >= 7)
indication for the application of antibiotics and probiotics
Age >=18 years
Informed consent
The exclusion criteria are on the listing.
What it tests, as registered
Tryptophan 25mg/kg bodyweight; Placebo
Registered summary
Patients with a pouch frequently suffer from chronic inflammation of the intestinal tract, called pouchitis. Pouchitis is routienly treated with repeated courses of antibiotics and probiotics, which does not stop the inflammation from recurring and exposes the patients to the risk of developing antibiotic -resistant pouchitis. Experimental data suggest that the effectiveness of the antibiotic and probiotic treatment can be prolonged by high consumption of trypotophan, an aminoacid present in everyday food. The full summary is on the listing.
Where, as registered
No sites listed yet.
Not yet recruitingNCT07013656
Effects of Combined Administration of Calcium and L-tryptophan on Gut Functions and Blood Glucose in Healthy Humans
No phase
University of Adelaide
About 16 people
Starts Jun 28, 2025 (estimated)
In plain words A study of L-tryptophan in male participants 18 to 70, run by University of Adelaide. It plans to enroll about 16 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists male participants 18 to 70; healthy volunteers accepted. Conditions: Healthy.
Healthy, lean males (only men will be included in the study to avoid the confounding effects of the menstrual cycle on gastric emptying).
BMI: 19-25 kg/m2,
Weight-stable (i.e. <5% fluctuation) at study entry, which will be ascertained by a stable body weight in the preceding 3 months.
The exclusion criteria are on the listing.
What it tests, as registered
L-tryptophan; Combination of L-tryptophan + Ca-500; Combination of L-tryptophan + Ca-1000; Control
Registered summary
The intervention in this study consists of 75-minute intraduodenal infusions of isosmotic solutions containing either saline (control), L-tryptophan, or calcium combined with L-tryptophan. Participants enrolled into the study will receive, in a randomised, double-blind fashion either (i) saline (control), (ii) L-tryptophan at a rate of 0.1 kcal/minute, (iii) combination of L-tryptophan (0.1 kcal/minute) + 500 mg calcium, or (iv) combination of L-tryptophan (0.1 kcal/minute) + 1000 mg calcium in four separate sessions, each of which will be separated by at least 4 (and up to 10) days. The full summary is on the listing.