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
Endometriosis and Migraine
Washington University School of Medicine
- Location
- St Louis, MO
- Eligibility basics
- Ages 12–45 · Women only
- RecruitingHealthy volunteers
The Increasing Mindfulness Engagement Project
Florida State University
- Location
- Tallahassee, FL
- Eligibility basics
- Ages 18–29
- RecruitingHealthy volunteers
PAIRS: Friend-Based AISA Intervention
State University of New York at Buffalo
- Location
- Buffalo, NY
- Eligibility basics
- Ages 18–24 · Women only
- RecruitingHealthy volunteers
Fiber Food Introduction in Pediatric Short Bowel Syndrome
Children's Hospital of Philadelphia
- Location
- Philadelphia, PA
- Eligibility basics
- Ages 4 mo–18
- RecruitingHealthy volunteers
MRI Neurofeedback and Brain Circuits Related to Motivation in Healthy Participants
Duke University
- Location
- Durham, NC
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Robot-assisted Training in Children With CP
Cook Children's Health Care System
- Location
- Fort Worth, TX
- Eligibility basics
- Ages 6–18
- RecruitingHealthy volunteersPhase 4
Disparities in Emergency Contraceptive Metabolism Dictate Efficacy
Oregon Health and Science University
- Location
- Portland, OR
- Eligibility basics
- Ages 18–40 · Women only
- RecruitingHealthy volunteers
Sexual Health Advocacy for Guys - a Text Messaging-based HIV Prevention Program for Guys Who Are Into Guys
Center for Innovative Public Health Research
- Location
- San Clemente, CA
- Eligibility basics
- Ages 13–22 · Men only
- RecruitingHealthy volunteers
Abuse Liability and Appeal of Oral Nicotine Products
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 21–25
- RecruitingHealthy volunteers
Predicting Future Errors During Skill Performance
National Institute of Neurological Disorders and Stroke (NINDS)
- Location
- Bethesda, MD
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Measuring How Quickly the Eye Focuses After Sustained Viewing of Close-up Images and Videos
Rochester Institute of Technology
- Location
- Rochester, NY
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Exosome Cargo From Preeclampsia Patients
University of Alabama at Birmingham
- Location
- Birmingham, AL
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteers
PATHS-UP Health Behavior Self-monitoring Mobile App for Adolescents
Baylor College of Medicine
- Location
- Houston, TX
- Eligibility basics
- Ages 12–18
- RecruitingHealthy volunteers
Immunomodulatory Effects of Fasting in Healthy Adults
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 20–40
- RecruitingHealthy volunteers
Young Adult Tobacco/Nicotine and Cannabis Co-use
Medical University of South Carolina
- Location
- Charleston, SC
- Eligibility basics
- Ages 18–25
- RecruitingHealthy volunteersPhase 2
Brain Blood Vessel Responses to Changes in Blood Flow: Younger Cohort
University of Wisconsin, Madison
- Location
- Madison, WI
- Eligibility basics
- Ages 20–40
- RecruitingHealthy volunteers
Neural and Metabolic Factors in Carbohydrate Reward
Virginia Polytechnic Institute and State University
- Location
- Roanoke, VA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Cannabis Observations on Brain Waves, Retrieval, and Attention: Experiment 4
L. Cinnamon Bidwell
- Location
- Boulder, CO
- Eligibility basics
- Ages 21–40
- RecruitingHealthy volunteers
Harvesting Health: Advancing Nutrition and Wellness for Moms and Babies
Texas A&M University
- Location
- College Station, TX + 2 other US sites
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteers
Cognitive Outcomes After Brain Substructure-informed Radiation Planning in Pediatric Patients
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
- Location
- Washington D.C., DC + 1 other US site
- Eligibility basics
- Ages 1–26
- RecruitingHealthy volunteers
Developing a Nutritional Supplement to Increase Collagen Synthesis in People
University of California, Davis
- Location
- Davis, CA
- Eligibility basics
- Ages 18–30
- RecruitingHealthy volunteers
Kids With Iron Deficiency and Scoliosis
Columbia University
- Location
- New York, NY
- Eligibility basics
- Ages 10–26
- RecruitingHealthy volunteers
MyPEEPS Mobile Plus: A Multi-Level HIV Prevention Intervention for Young MSM
Columbia University
- Location
- New York, NY
- Eligibility basics
- Ages 16–25 · Men only
- RecruitingHealthy volunteers
Delivering HOPE (Helping Women Optimize Prenatal Equity)
University of Arkansas
- Location
- Corning, AR + 6 other US sites
- Eligibility basics
- Ages 16–44 · Women only
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.