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
Breathing & Blood Pressure
Florida State University
- Location
- Tallahassee, FL
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Modulation of Brain Oscillations Underlying Working Memory
Massachusetts General Hospital
- Location
- Charlestown, MA
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteersPhase 2
Long Term Evaluation of Scapular-inserted Contraceptive Implants
Yale University
- Location
- Aurora, CO + 1 other US site
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteers
Handgrip Training and Brain Blood Flow Regulation
Florida State University
- Location
- Tallahassee, FL
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Real-World Episodic Memory
Florida State University
- Location
- Tallahassee, FL
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
fMRI Studies of Memory and Perception
Florida State University
- Location
- Tallahassee, FL
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Supplementation of Cholecalciferol and Related Active Metabolites Through Bioenhancing Layer's Eggs
Cornell University
- Location
- Ithaca, NY
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteers
Vascular Function in Adults With Down Syndrome
University of Nevada, Las Vegas
- Location
- Las Vegas, NV
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Effects of Pre-Run Nutritional Supplements During a Fixed-Pace 5 km Treadmill Run
St. Louis University
- Location
- St Louis, MO
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Genetic Inclusion by Virtual Evaluation
Baylor College of Medicine
- Location
- Edinburg, TX
- Eligibility basics
- Ages 0 mo–18
- RecruitingHealthy volunteersPhase 2
Low Dose Aspirin for the Prevention of Postpartum Related Breast Cancer
Mayo Clinic
- Location
- Jacksonville, FL + 3 other US sites
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteers
A Novel Intervention for Weight Loss in Young Adults
University of Chicago
- Location
- Chicago, IL
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteers
Multisensory Processing of Alcohol Cues in Young Adult Binge Drinkers
Rochester Institute of Technology
- Location
- Rochester, NY
- Eligibility basics
- Ages 18–25
- RecruitingHealthy volunteers
Wakaya: Rising Up for Choctaw Youth Health
University of Washington
- Location
- Durant, OK + 1 other US site
- Eligibility basics
- Ages 12–19
- RecruitingHealthy volunteers
Two-Week Stair-Climbing Exercise Snacks and Metabolic Health in Adults With Overweight or Obesity: A Pilot Study
St. Louis University
- Location
- St Louis, MO
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteers
Does a Periaqueductal Gray-vagus Nerve Interface Malfunction Explain the Nat hx With Its Numerous Co-morbidities?
Virginia Commonwealth University
- Location
- Richmond, VA
- Eligibility basics
- Ages 12–21 · Women only
- RecruitingHealthy volunteers
Acute Mental Fatigue and Muscle Strength
Florida Institute for Human and Machine Cognition
- Location
- Pensacola, FL
- Eligibility basics
- Ages 18–39
- RecruitingHealthy volunteers
Deceased Uterine Transplant in Absolute Uterine Infertility (AUIF)
Brigham and Women's Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 18–40 · Women only
- RecruitingHealthy volunteers
Development and Validation of Learning and Decision-Making Tasks
National Institute on Drug Abuse (NIDA)
- Location
- Baltimore, MD
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Effects of Lean Beef Consumption on Cardiometabolic Health and Gut Microbiome
University of Missouri-Columbia
- Location
- Columbia, MO
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Wear Experience With Daily Disposable Contact Lenses for Astigmatism Over a Long-Wear Day
Ohio State University
- Location
- Columbus, OH
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteers
Protein Supplementation During Luteal Phase to Stop Protein Degradation
Sam Houston State University
- Location
- Conroe, TX
- Eligibility basics
- Ages 18–35 · Women only
- RecruitingHealthy volunteers
Comparison of Microbiome Changes in Healthy Adults Following Ketone Ester Consumption
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteers
Comparison of Two Different Sperm Processing Methods and Their Effects on Sperm DNA Fragmentation and Embryo Development
Richard Kordus, PhD, HCLD (ABB)
- Location
- Greenville, SC
- Eligibility basics
- Ages 18–34
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.