NCT05722860

Brief Summary

The effect of L-Citrulline is well studied in relation to muscle strength, exhaustion, exercise performance, and endothelial function in health and disease. This study will extend current body of knowledge and will investigate the effect of L-Citrulline on brain vascular function.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
20

participants targeted

Target at P25-P50 for phase_1

Timeline
Completed

Started Jan 2024

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

February 1, 2023

Completed
9 days until next milestone

First Posted

Study publicly available on registry

February 10, 2023

Completed
11 months until next milestone

Study Start

First participant enrolled

January 3, 2024

Completed
11 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 28, 2024

Completed
1 month until next milestone

Study Completion

Last participant's last visit for all outcomes

December 28, 2024

Completed
Last Updated

March 12, 2026

Status Verified

March 1, 2026

Enrollment Period

11 months

First QC Date

February 1, 2023

Last Update Submit

March 10, 2026

Conditions

Aging

Keywords

L-Citrulline

Outcome Measures

Primary Outcomes (3)

  • Change in neurovascular coupling using functional near infrared spectroscopy (fNIRS)

    Functional near infrared spectroscopy (fNIRS) will be performed during the cognitive n-back task. fNIRS approach generates data that represent a relative change in oxygenated and deoxygenated hemoglobin measured over the cortical brain tissues. Neurovascular coupling will be evaluated as a change in oxy- and deoxy-hemoglobin between before and after treatment. Units of measure - beta. Reported as a %change from baseline, before and after treatment.

    1 week

  • Change in neurovascular coupling using the dynamic retinal vessel analysis

    Flicker light-induced dilation of the retinal vessels (percentage increase over baseline diameter) will be measured in the right or left eye of each study participant using the Dynamic Vessel Analyzer (DVA, IMEDOS Systems, Jena, Germany). Units of measure mm, reported as a %change from baseline, before and after treatment.

    1 week

  • Change in neuronal activity

    EEG signal will be collected to generate spectral data. These data will be used for comparison of EEG activity between before and after treatment. Units of measure - power spectral density. Reported as a %change from baseline, before and after treatment.

    1 week

Secondary Outcomes (11)

  • Change in microvascular endothelial function

    1 week

  • Change in macrovascular endothelial function

    1 week

  • Change in Glycocalyx - perfused boundary region

    1 week

  • Change in capillary density

    1 week

  • Change in red blood cell velocity

    1 week

  • +6 more secondary outcomes

Study Arms (1)

L-Citrulline

EXPERIMENTAL

L-Citrulline 50 g/day per os for 1 week

Drug: L-Citrulline, capsule

Interventions

L-Citrulline, capsuleDRUG

5g/daily dose for the duration of 1 week intervention

L-Citrulline

Eligibility Criteria

Age18 Years - 90 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Age 21-45 and ≥55-90 years of age
  • Adequate hearing and visual acuity to participate in the examinations
  • Ability to read and write in English
  • Competence to provide informed consent

You may not qualify if:

  • Active CNS disease including multiple sclerosis, uncontrolled seizures, active brain cancer
  • Cerebrovascular accident other than TIA within 60 days prior to Visit 0
  • Major psychiatric disease, including major depression not currently controlled on medications, alcohol or drug abuse
  • Treatment with other Citrulline enhancers (L-Arginine, L-Citrulline Malate) within 4 weeks prior to Visit 0
  • Any other medical condition which, in the opinion of investigator, would render the patient inappropriate or too unstable to complete the study protocol

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Andriy Yabluchanskiy

Oklahoma City, Oklahoma, 73117, United States

Location

MeSH Terms

Interventions

CitrullineCapsules

Intervention Hierarchy (Ancestors)

Amino Acids, DiaminoAmino AcidsAmino Acids, Peptides, and ProteinsDosage FormsPharmaceutical Preparations

Study Officials

  • Andriy Yabluchanskiy, MD, PhD

    University of Oklahoma

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NA
Masking
NONE
Masking Details
Open label
Purpose
BASIC SCIENCE
Intervention Model
SINGLE GROUP
Model Details: Open label single arm study
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 1, 2023

First Posted

February 10, 2023

Study Start

January 3, 2024

Primary Completion

November 28, 2024

Study Completion

December 28, 2024

Last Updated

March 12, 2026

Record last verified: 2026-03

Data Sharing

IPD Sharing
Will not share

PhysioNet

Locations

US(1)