2 registrations that name 5-HTP 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 2 registrations
Status
Phase
1US sites across 1 state
1
2 to 4
5 to 19
20 or more
All 2 registrations
RecruitingNCT04160910
5HTP Regulation Of Asthma In Children
Phase 2
Indiana University
About 20 people
Started Feb 11, 2021
In plain words A Phase 2 study of 5-HTP in people 8 to 18, run by Indiana University. It plans to enroll about 20 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 8 to 18. Conditions: Mild or Moderate Asthma With Allergic Sensitization.
Age 8-18 Years of Age
Mild to Moderate Asthma based on ATS guidelines
Positive Allergy Test (positive skin or serum IgE)
Weight ≥ 70 lbs (32 kg)
4 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
5-Hydroxytryptophan; Placebo
Registered summary
The purpose of this study is to learn more about if taking a supplement called 5-hydroxytryptophan (5HTP) can improve breathing and anxiety symptoms related to asthma. To help learn more subjects will either be assigned to a group that is taking the supplement (5HTP) or a group that is taking a placebo. This will be decided randomly. Later in the study subjects will crossover to the other group.There are 5 study visits over the course of about 12 weeks.
Where, as registered
1 US site in 1 state.
RecruitingNCT07777328
The Effect of 5-hydroxytryptophan on ADHD Traits and Eye Movements
No phase
University of Sheffield
About 150 people
Started Nov 25, 2025
In plain words A study of 5-HTP in people 18 to 65, run by University of Sheffield. It plans to enroll about 150 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 65; healthy volunteers accepted. Conditions: Attention Deficit and Hyperactivity Disorder (ADHD); Attention Deficit Hyperactivity Disorder in Adults; Attention Deficits.
18-65 years of age
Normal or corrected to normal vision with contact lenses.
Score of <9 or >14 on the ASRS v5 (assessed in pre screen questionnaire)
The aim of this project is to look at the impact of 5-Hydroxytryptophan (5-HTP) on distractibility. 5-HTP is the precursor to the neurotransmitter serotonin and is a chemical that the body produces naturally. There is evidence that distractibility is associated with a decreased level of serotonin. This research aims to see if giving people 5-HTP will alter their distractibility, which will form part of an initial assessment as to whether 5-HTP could be used to support people with attention problems. The full summary is on the listing.