Bioavailability and AUCNCT06977854
The Objective of This Study Was to Compare and Quantify the Bioavailability of Citrulline Byproducts in Blood Samples and in Urine Samples After a Single Dose of the Assigned Dietary Supplement. The Treatment Arms Containing the Following Molecules: Citrulline HCL and L-Citrulline,
An observational study of Bioavailability and AUC, run by Vireo Systems, Inc. at 1 site in United States.
Trial summary
Citrulline dietary supplements are of interest for improving cardiovascular and exercise performance. The health benefits of citrulline are attributable to its ability to increase arginine levels in the body through the intestinal-renal arginine conversion pathway. Read more about this study
- Who is it for?
- Ages 18 to 64 yearsHealthy volunteers can take part
- Conditions the study is for
- Bioavailability and AUC
- What is being tested?
- Removal from study. In case of adverse event, subject treated for the AE. and removal from study
- How many people
- 32 participants
- Where
- 1 siteUnited States
- Study dates
- 13 Jul 2024to 27 Jul 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 64 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: healthy males and females ages 18-64
Who may be able to join
- healthy and hydrated male or female ages 18-64; agrees to refrain from citrulline-rich foods; able and willing to fast 12 hours prior to baseline visit; willing to have blood and urine collections as dictated in the protocol; females of child bearing age have some type of birth control.
Who cannot join
- female subject is pregnant; allergies or sensitivities to citrulline products; history of losing consciousness during blood collection;past medical history of iron deficiency; history of or current treatment for hypertension, coronary heart disease; or angina pectoris; known kidney function issues or disorders; being treated with ACE inhibitors; cancer diagnosis within 5 years of visit; history of chronic disease.
Trial locations and contacts
1 site in 1 country.
United States1 site
Princeton Consumer Research
Raritan, New Jersey, 08869
About this study
Official title: A SINGLE CENTER, SINGLE-BLIND STUDY DESIGN IN HEALTHY SUBJECTS TO EVALUATE SEVERAL EFFECTS OF CITRULLINE SUPPLEMENTS
Citrulline dietary supplements are of interest for improving cardiovascular and exercise performance. The health benefits of citrulline are attributable to its ability to increase arginine levels in the body through the intestinal-renal arginine conversion pathway. From a dietary supplementation standpoint, citrulline offers advantages over arginine due to its reduced first-pass metabolism and ready conversion to arginine within the body. While L-citrulline is the most widely used citrulline dietary supplement, additional salt forms such as citrulline maleate and citrulline HCl may provide improvements in the delivery of arginine to the body. The present study compared the single-dose pharmacokinetics of L-citrulline and citrulline HCl formulations in healthy human subjects. A total of 17 subjects were randomly assigned to groups receiving either 6 g of L-citrulline, 6 g of citrulline HCl or 2 g of citrulline HCl. The resulting increases in citrulline and arginine in plasma and urine samples were determined using liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM/MS). All citrulline dietary supplements examined produced time-dependent increases in plasma citrulline and arginine. Both maximal plasma concentration (Cmax) and area under the plasma vs time curve (AUC) for citrulline were modestly reduced in the 6 g citrulline HCl treatment group, the resulting arginine Cmax and AUCs were similar for both L-citrulline and citrulline HCl at the 6 g dose. While the 2 g dose of citrulline HCl had reduced Cmax and AUC values compared to 6 g doses, the time to reach peak levels of arginine were significantly shorter. Furthermore, examination of the relative arginine bioavailability achieved with the 6 g and 2 g citrulline HCl compared to the 6 g L-citrulline was approximately 120% and 215%, respectively, consistent with an improved citrulline to arginine conversion efficiency with the citrulline HCl formulations.
- Conditions
- Bioavailability and AUC
- Being tested
- Removal from study. In case of adverse event, subject treated for the AE., removal from study
- Keywords
- Citrulline,Arginine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Removal from study. In case of adverse event, subject treated for the AE.Other
The participation of a subject in this study may have been discontinued for any of the following reasons:
- the subject wished to withdraw from study participation;
- if, in the opinion of the Investigator, it was in the best interest of the subject;
- suspected adverse effects from the test article;
- inter-current illness;
- violation of the prohibitions and restrictions;
- development of an exclusion criteria. Subjects were free to withdraw at any time and need not give a reason, however, every reasonable attempt was made to ascertain such reasons. The data for those subjects who were withdrawn was included in the final clinical report but may be excluded from final data analysis.
removal from studyOther
The participation of a subject in this study may have been discontinued for any of the following reasons:
- the subject wished to withdraw from study participation;
- if, in the opinion of the Investigator, it was in the best interest of the subject;
- suspected adverse effects from the test article;
- inter-current illness;
- violation of the prohibitions and restrictions;
- development of an exclusion criteria. Subjects were free to withdraw at any time and need not give a reason, however, every reasonable attempt was made to ascertain such reasons. The data for those subjects who were withdrawn was included in the final clinical report but may be excluded from final data analysis.
| Study group | Role | What they receive |
|---|---|---|
| Generally healthy male and female subjects aged 18-64 | Not described Receives: Other: Removal from study. In case of adverse event, subject treated for the AE.; Other: removal from study |
What is being measured
The primary outcome is the main question the study is designed to answer.
Arginine levels in plasma
Measured blood plasma arginine levels at various time points.
Measured: 0-180 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 May 2025
- Study start13 Jul 2024
- Primary completion27 Jul 2024
- Study completion27 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bioavailability and AUCStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vireo Systems, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Princeton Consumer Research
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06977854
- Sponsor's protocol ID
- VIRUSE2R
- Status last verified
- May 2025
- First submitted
- 9 May 2025
- Last updated
- 18 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A SINGLE CENTER, SINGLE-BLIND STUDY DESIGN IN HEALTHY SUBJECTS TO EVALUATE SEVERAL EFFECTS OF CITRULLINE SUPPLEMENTS
- ClinicalTrials.gov ID
- NCT06977854
- Acronym / sponsor ID
- VIRUSE2R
- Conditions
- Bioavailability and AUC
- Keywords
- Citrulline,Arginine
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Vireo Systems, Inc.Industry (pharma, biotech, devices)
- Collaborators
- Princeton Consumer Research
- Study start
- 13 Jul 2024 (actual)
- Primary completion
- 27 Jul 2024 (actual)
- Study completion
- 27 Jul 2024 (actual)
- First posted
- 18 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Citrulline dietary supplements are of interest for improving cardiovascular and exercise performance. The health benefits of citrulline are attributable to its ability to increase arginine levels in the body through the intestinal-renal arginine conversion pathway. From a dietary supplementation standpoint, citrulline offers advantages over arginine due to its reduced first-pass metabolism and ready conversion to arginine within the body. While L-citrulline is the most widely used citrulline dietary supplement, additional salt forms such as citrulline maleate and citrulline HCl may provide improvements in the delivery of arginine to the body. The present study compared the single-dose pharmacokinetics of L-citrulline and citrulline HCl formulations in healthy human subjects. A total of 17 subjects were randomly assigned to groups receiving either 6 g of L-citrulline, 6 g of citrulline HCl or 2 g of citrulline HCl. The resulting increases in citrulline and arginine in plasma and urine samples were determined using liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM/MS). All citrulline dietary supplements examined produced time-dependent increases in plasma citrulline and arginine. Both maximal plasma concentration (Cmax) and area under the plasma vs time curve (AUC) for citrulline were modestly reduced in the 6 g citrulline HCl treatment group, the resulting arginine Cmax and AUCs were similar for both L-citrulline and citrulline HCl at the 6 g dose. While the 2 g dose of citrulline HCl had reduced Cmax and AUC values compared to 6 g doses, the time to reach peak levels of arginine were significantly shorter. Furthermore, examination of the relative arginine bioavailability achieved with the 6 g and 2 g citrulline HCl compared to the 6 g L-citrulline was approximately 120% and 215%, respectively, consistent with an improved citrulline to arginine conversion efficiency with the citrulline HCl formulations.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Generally healthy male and female subjects aged 18-64 | – | Other: Removal from study. In case of adverse event, subject treated for the AE., Other: removal from study |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- healthy males and females ages 18-64
Key inclusion criteria (1 listed)
- healthy and hydrated male or female ages 18-64; agrees to refrain from citrulline-rich foods; able and willing to fast 12 hours prior to baseline visit; willing to have blood and urine collections as dictated in the protocol; females of child bearing age have some type of birth control.
Key exclusion criteria (1 listed)
- female subject is pregnant; allergies or sensitivities to citrulline products; history of losing consciousness during blood collection;past medical history of iron deficiency; history of or current treatment for hypertension, coronary heart disease; or angina pectoris; known kidney function issues or disorders; being treated with ACE inhibitors; cancer diagnosis within 5 years of visit; history of chronic disease.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Removal from study. In case of adverse event, subject treated for the AE.The participation of a subject in this study may have been discontinued for any of the following reasons: * the subject wished to withdraw from study participation; * if, in the opinion of the Investigator, it was in the best interest of the subject; * suspected adverse effects from the test article; * inter-current illness; * violation of the prohibitions and restrictions; * development of an exclusion criteria. Subjects were free to withdraw at any time and need not give a reason, however, every reasonable attempt was made to ascertain such reasons. The data for those subjects who were withdrawn was included in the final clinical report but may be excluded from final data analysis. | Other | Generally healthy male and female subjects aged 18-64 |
| removal from studyThe participation of a subject in this study may have been discontinued for any of the following reasons: * the subject wished to withdraw from study participation; * if, in the opinion of the Investigator, it was in the best interest of the subject; * suspected adverse effects from the test article; * inter-current illness; * violation of the prohibitions and restrictions; * development of an exclusion criteria. Subjects were free to withdraw at any time and need not give a reason, however, every reasonable attempt was made to ascertain such reasons. The data for those subjects who were withdrawn was included in the final clinical report but may be excluded from final data analysis. | Other | Generally healthy male and female subjects aged 18-64 |
Primary outcome
Arginine levels in plasma
Time frame: 0-180 minutes
Measured blood plasma arginine levels at various time points.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 May 2025.
Related trials for Bioavailability and AUC
Active, not recruiting
Bioavailability of Phlorotannins and Carotenoids Following the Intake of Crackers Fortified With Seaweed
Bioavailability Heathy Volunteers, Bioavailability and AUC
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Bioavailability and AUC, run by Vireo Systems, Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Arginine levels in plasma (time frame: 0-180 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 May 2025.