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.

The objective of this study is to test the hypothesis that over-the-counter amino acid supplement 5HTP (isolated from the plant Griffonia Simplifolia) reduces human allergic lung responses and consequently improves lung function. The primary outcome is the change in FEV1. We anticipate the 5HTP at the proposed doses will improve lung function as in preclinical studies that used clinically relevant 5HTP. Secondary outcomes will be blood eosinophil counts and reduced symptoms for anxiety/depression, as seen in changes in the anxiety-depression scores from questionnaires (CES-DC & SCARED). The results from these studies have the transformative potential to influence approaches to improve lung function and asthma-associated anxiety/depression.

• Aim 1: Test that 5HTP improves lung function in children with allergic asthma
• Aim 2: Test that 5HTP reduces eosinophil numbers in the blood and nasal fluid of patients with asthma from Aim 1
• Aim 3: Test that 5HTP decreases lung inflammation, increases cortisol and prolactin without altering systemic plasma concentrations of 5HTP, serotonin, 5-hydroxyindoleacetic acid (5-HIAA), and dopamine

Inclusion Criteria:

• 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)

• CES-DC cut-off ≥ 15 (total score range is 0 to 60) or SCARED cut-off

  • 25 (total score range is 0 to 142)

• Ability to comply with study visits and study procedures

• Informed Consent by participant and if applicable the parent or legal guardian

Exclusion Criteria:

• Currently taking a SSRI
• Taking a leukotriene inhibitor (montelukast, Zileuton)
• Severe Asthma Based on ATS Guidelines
• Taking a biologic medication (omalizumab, mepolizumab, benralizumab, dupilumab)
• Medical History of Adverse Reaction to 5HTP
• Physical findings that would compromise the safety of the study or the quality of the study data