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Completed Early Phase 1 Interventional Accepts healthy volunteers Results available

Brain Dopamine Function in Human Obesity

ClinicalTrials.gov ID: NCT03648892

Public ClinicalTrials.gov record NCT03648892. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 4, 2026, 5:12 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Background: Dopamine is a natural chemical in the brain that may influence eating behavior and physical activity. Researchers want to measure the brain s dopamine activity and understand how it differs in people with obesity. Objective: To better understand how brain function, particularly dopamine activity, relates to body weight and eating behavior. Individuals may be able to participate if they: Have a BMI of at least 18.5 kg/m2 Are weight-stable and generally healthy Are between ages 18-45 years Have normal blood pressure Are not using illegal drugs (based on urine drug screen) Are not following a special diet Do not have metal implants Design: Participants will be screened with: * Medical history * Physical exam * Questionnaires and an interview to see if it is safe to have a PET/MRI scan * Fasting blood and urine tests * Participants will eat a special diet given to them for the 5 days before their inpatient visit. Participants will have a 5-day inpatient visit. Some days include blood and urine tests. Each day includes surveys and tests to measure habits and likes/dis-likes. A sample schedule may be: Day 1: Participants will wear a monitor that uses a needle below the skin to measure glucose. Their body fat will be measured with low-dose x-rays Day 2: Participants will have a PET scan. They will lie on a table that slides in and out of a donut-shaped scanner. They will be injected with a small amount of a radioactive substance and wear a cap on their head. Day 3: Participants will have an MRI. They will lie on a table that slides in and out of a scanner. Day 4: Participants will have another PET scan. This time, they will drink a milk shake during a break from the scanner. Then, they will go back inside the scanner for the end of their scan. Day 5: Participants will wear a hood for up to 40 minutes to measure their breathing. They will also drink special water and collect samples of their urine to measure the rate they burn energy. For 12 months after the visit, participants will track their weight and physical activity daily using a special scale and activity monitor. A few times over the year, the study team will send participants special activity monitors to use for 7 days at a time. Participants will have an in-person 1-day follow-up visit. This includes most tests except for PET scanning....

Study identification

NCT ID
NCT03648892
Recruitment status
Completed
Study type
Interventional
Phase
Early Phase 1
Enrollment
61 participants

Conditions and interventions

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Accepts healthy volunteers

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Sep 20, 2018
Primary completion
Mar 30, 2022
Completion
Feb 16, 2023
Last update posted
Jul 10, 2023

2018 – 2023

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
National Institutes of Health Clinical Center Bethesda Maryland 20892

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT03648892, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jul 10, 2023 · Synced Sep 4, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT03648892 live on ClinicalTrials.gov.

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