Who can join
Studies for younger adults
These studies accept adults from 21 or younger and set an upper age limit of 45 or below, so they are aimed at younger adults. Being in the age range does not mean you qualify; screening decides.
674 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
Studies
- RecruitingHealthy volunteers
Changes in 24-hour Activity Cycle Behaviors During a Time-Restricted Eating Intervention in College-Aged Women
University of Georgia
- Location
- Athens, GA
- Eligibility basics
- Ages 18–26 · Women only
- RecruitingHealthy volunteers
Testing the Adipose Expandability Hypothesis In Vivo During Overfeeding
Pennington Biomedical Research Center
- Location
- Baton Rouge, LA
- Eligibility basics
- Ages 18–42
- RecruitingHealthy volunteers
Circadian Rhythms and Homeostatic Sleep Drive and Their Effect on Reward and Cognitive Control Systems in Adolescents
University of Pittsburgh
- Location
- Pittsburgh, PA
- Eligibility basics
- Ages 13–18
- RecruitingHealthy volunteers
Determining the Effect of Six Weeks of Cannabis Abstinence on Fronto- Striatal fMRI Markers in Adolescents With Cannabis Use Disorder (ABSCAN)
University of Minnesota
- Location
- Minneapolis, MN
- Eligibility basics
- Ages 15–18
- RecruitingHealthy volunteers
Cannabis Effects on Sleep, Circadian Rhythms, and Light Sensitivity in Young Adults
University of Pittsburgh
- Location
- Pittsburgh, PA
- Eligibility basics
- Ages 18–25
- RecruitingHealthy volunteers
Neuroimaging Approaches to Improve Prediction of Smoking Initiation and Nicotine Escalation in Young Adult ENDS Users
University of Georgia
- Location
- Athens, GA
- Eligibility basics
- Ages 18–29
- RecruitingHealthy volunteers
Gastric Assessment of Pediatric Patients Undergoing Surgery
Boston Children's Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 2–18
- RecruitingHealthy volunteers
Examining the Impact of Exercise Training on Vascular Dysfunction in Individuals With Mental Health Disorders - Study 3
Virginia Commonwealth University
- Location
- Richmond, VA
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Effect of Menthol on ENDS Users' Addiction and Exposure
Florida International University
- Location
- Miami, FL
- Eligibility basics
- Ages 21–35
- RecruitingHealthy volunteers
Quitxt Mobile Text Messaging Cessation Research Study
The University of Texas Health Science Center at San Antonio
- Location
- San Antonio, TX
- Eligibility basics
- Ages 18–29
- RecruitingHealthy volunteers
The Modulatory Effect of Female Sex Hormones on Spinal Neuroplasticity
University of Texas Southwestern Medical Center
- Location
- Dallas, TX
- Eligibility basics
- Ages 18–39
- RecruitingHealthy volunteers
Pneumatic Compression vs Blood Flow Restriction for Muscle Recovery
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–30
- RecruitingHealthy volunteers
My Life and My Experiences Project
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Ages 12–18
- RecruitingHealthy volunteers
Modulating Temporoparietal Junction Mentalizing-Related Activity in Autism Spectrum Disorder (ASD) Using Transcranial Magnetic Stimulation (TMS)
Yale University
- Location
- Hartford, CT
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Assessments of Adipogenesis, Lipid Turnover and Cellular Composition in Adipose Tissue in Response to Endurance Exercise
AdventHealth Translational Research Institute
- Location
- Orlando, FL
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Examining the Role of Female Endogenous Sex Hormones in Eccentric Exercise
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–35 · Women only
- RecruitingHealthy volunteers
Breast Cancer Study Tracking Risk Awareness of Alcohol Consumption and Improving Knowledge in Young Adult Women
Ohio State University Comprehensive Cancer Center
- Location
- Columbus, OH
- Eligibility basics
- Ages 18–25 · Women only
- RecruitingHealthy volunteers
Exercise and Carotid Artery Function in Metabolic Syndrome
University of Wisconsin, Madison
- Location
- Madison, WI
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteers
Energy Dense Fueling for Cold-Weather Operations
United States Army Research Institute of Environmental Medicine
- Location
- Natick, MA
- Eligibility basics
- Ages 18–39
- RecruitingHealthy volunteers
Mechanism of Ketogenic Diet-Induced Hypercholesterolemia
Washington University School of Medicine
- Location
- St Louis, MO
- Eligibility basics
- Ages 18–39
- RecruitingHealthy volunteers
Speech-in-noise Perception in Autism and Fragile X
Children's Hospital Medical Center, Cincinnati
- Location
- Cincinnati, OH
- Eligibility basics
- Ages 15–35
- RecruitingHealthy volunteers
Health Information Technology to Reduce Disparities in Adolescent Health Outcomes: A Pragmatic Trial
Children's National Research Institute
- Location
- Washington D.C., DC
- Eligibility basics
- Ages 15–21
- RecruitingHealthy volunteers
Retraining and Control Therapy (ReACT) R33 Phase
University of Alabama at Birmingham
- Location
- Birmingham, AL
- Eligibility basics
- Ages 11–18
- RecruitingHealthy volunteersPhase 2/Phase 3
Dissolved Phase HXe-129 MRI: A Novel Biomarker to Quantify Pulmonary Pathology
Y. Michael Shim, MD
- Location
- Durham, NC + 1 other US site
- Eligibility basics
- Ages 18–35
Questions
If I fit this group, will I qualify?
Not necessarily. Age and sex limits are only the first filter. Each study has its own inclusion and exclusion criteria, and the research team decides at screening.
Where do these age and sex limits come from?
From the eligibility section of each study’s official ClinicalTrials.gov record. We don’t infer eligibility from anything else.