Asthma L-Citrulline Pilot Study

Inclusion Criteria: * Adequate completion of informed consent process with written documentation * Male and female patients, 18 - 70 years old, inclusive * Physician diagnosis of asthma (for medical records, ICD 10 coding for physician's diagnosis) * All racial/ethnic backgrounds may participate * BMI ≥ 30 * Treatment of controller asthma medication(s) ≥ 4 weeks * Smoking history ≤10 pack years and no smoking in the last year * V1 eNO ≤ 30ppb (may be repeated 3x during visit; lowest ppb will be kept) Exclusion Criteria: * Respiratory tract infection within the 4 weeks prior to the study (may re-enroll after 4 weeks). * Oral or systemic corticosteroid burst (for any indication) within the 4 weeks * One-time doses, such as intra-articular injections into a shoulder or knee joint, require a 2-week washout. * Asthma-related ER visit within the previous 4 weeks of Visit 1 * Significant concomitant medical illness, including (but not limited to) * Heart disease * Cancer * Uncontrolled diabetes, * Chronic renal failure (creatinine \> 2.0) at Visit 1 (Associated with higher ADMA levels) * Untreated sleep apnea * Other chronic lung/respiratory diseases (COPD, IPF, etc.) * High dose inhaled steroids (\> 1000 mcg/day of Fluticasone or equivalent) * Current statin use (statins lower ADMA levels); patients may stop statins with approval from their primary physician and enroll after a 6-week washout * Positive urine pregnancy test at Visit 1 or at any time during the study * Intolerance or allergy to L-arginine or L-citrulline * Concomitant use of PDE5 drugs or oral mononitrates * Participation in an intervention study, use of investigative drugs within the past 30 days or plans to enroll in such a trial during the study * Unable or unlikely to complete study assessments in the opinion of the Investigator * Study intervention poses undue risk to patient in the opinion of the Investigator * Breastfeeding