Adults with Poorly Controlled Asthma - Clinical Trial

What is the Purpose of this Study?

We are doing this study to find out if L-citrulline (the study drug) will help improve asthma symptoms when taken daily. This study is important because managing symptoms of asthma can improve quality of life and long-term health.

What is the Condition Being Studied?


Who Can Participate in the Study?

Adults ages 18-65 who:

  • Are not pregnant
  • Have been diagnosed with asthma by a healthcare provide at least 6 months ago
  • Are currently taking an ICS or ICS/LABA medication such as Symbicort, Pulmicort, Advair, or QVar
  • Have a BMI greater than 30

For more information about who can join this study, please contact the study team at or 919-479-0861.

Age Group

What is Involved?

If you choose to join this study, you will:

  • Answer questionnaires
  • Have your lung function tested
  • Give blood and urine samples
  • Undergo methacholine challenges (breathing tests to test your airways)

Study Dosing Period: During this period of the study, you will get a random assignment (like flipping a coin) to 1 of 2 groups:

  • One group will take the study drug (L-citrulline) by mixing a powder into water once a day for 7 weeks
  • The other group will take a placebo (sugar powder) by mixing the powder into water once a day for 7 weeks

All study participants will:

  • Complete an asthma questionnaire 4 weeks after your first dose
  • Complete breathing tests before and after taking the first and last dose of the study drug/placebo

You also have the option to participate in a bronchoscopy where cells from your lungs will be collected to study how well L-citrulline works.

Study Details

Full Title
SANDIA: Supplementing L-citrulline to overweight late Asthma oNset phenotypes to increase airway L-arginine/ADMA ratio and Improve Asthma control
Principal Investigator
Protocol Number
IRB: PRO00104357
NCT: NCT03885245
Phase Pilot
Enrollment Status
Open for Enrollment