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 volunteersPhase 1
Safety and Immunogenicity of V540B in Healthy Adults (V540B-002).
Merck Sharp & Dohme LLC
- Location
- Hallandale, FL + 1 other US site
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 1
A Study to Evaluate Safety, Tolerability, and Immunogenicity of V350A and V350B in Healthy Participants (V350-001).
Merck Sharp & Dohme LLC
- Location
- Kansas City, MO + 5 other US sites
- Eligibility basics
- Ages 12–30
- RecruitingHealthy volunteersPhase 1
Phase 1 Study of Intravaginal KB15A
ZabBio Inc.
- Location
- Norfolk, VA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersPhase 1
Study of MAR002 in Healthy Men
Marea Therapeutics
- Location
- Tempe, AZ
- Eligibility basics
- Ages 18–40 · Men only
- RecruitingHealthy volunteersOvernight stay mentioned
Eating to Adjust the Timing System
Brigham and Women's Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersOvernight stay mentioned
Can Food Timing Reduce Your Diabetes Risk?
Brigham and Women's Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 1
Safety Study of MucoCept-CVN
Craig Cohen, MD, MPH
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersPhase 1
Use of Pulsatile Intravenous FSH to Mitigate Reprometabolic Syndrome
University of Colorado, Denver
- Location
- Aurora, CO
- Eligibility basics
- Ages 19–37 · Women only
- RecruitingHealthy volunteersPhase 1
The Effects of Cannabidiol on the Driving Performance of Healthy Adults by Dose and Sex
West Virginia University
- Location
- Morgantown, WV
- Eligibility basics
- Ages 18–30
- RecruitingHealthy volunteersPhase 1
Epstein-Barr Virus (EBV) gH/gL/gp42-Ferritin Nanoparticle Vaccine With or Without gp350-Ferritin in Healthy Adults With or Without EBV Infection
National Institute of Allergy and Infectious Diseases (NIAID)
- Location
- Bethesda, MD
- Eligibility basics
- Ages 18–29
- RecruitingHealthy volunteersPhase 1
Imaging Sex Differences in Smoking-Induced Pulmonary Inflammation
University of Pennsylvania
- Location
- Philadelphia, PA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersOvernight stay mentioned
Effect of Physical Activity Pattern on Cardiometabolic Health
Brigham and Women's Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 1
Gamma Oscillations as a Prognostic Marker for Ketamine Therapy in Treatment Resistant Depression
Texas A&M University
- Location
- Houston, TX + 1 other US site
- Eligibility basics
- Ages 21–45
- RecruitingHealthy volunteersEarly Phase 1
Imaging Mitochondrial Complex-I in Cocaine Use Disorder: a [F-18]BCPP-EF PET Study
Rajesh Narendran
- Location
- Pittsburgh, PA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 1/Phase 2
Study of Cannabidiol and Neuroimaging on Stress
Icahn School of Medicine at Mount Sinai
- Location
- New York, NY
- Eligibility basics
- Ages 18–25
- RecruitingHealthy volunteersOvernight stay mentioned
Functional Magnetic Resonance Imaging Sleep Study With Auditory Stimuli
National Institute of Neurological Disorders and Stroke (NINDS)
- Location
- Bethesda, MD
- Eligibility basics
- Ages 18–34
- RecruitingHealthy volunteersEarly Phase 1
Light Therapy for Obsessive-compulsive Disorder (OCD)
Washington University School of Medicine
- Location
- St Louis, MO
- Eligibility basics
- Ages 17–35
- RecruitingHealthy volunteersEarly Phase 1
Antidepressant Therapy for Improved Blood Vessel Health After Preeclampsia
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Sex Disparities in Hypoxic Vasodilation and Impact of Obesity
University of Missouri-Columbia
- Location
- Columbia, MO
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersEarly Phase 1
Endometriosis and Microvascular Dysfunction: Role of Inflammation
Penn State University
- Location
- University Park, PA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersPhase 1
Mifepristone vs Misoprostol
Montefiore Medical Center
- Location
- The Bronx, NY
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Autonomic Control of the Circulation and VDR
Milton S. Hershey Medical Center
- Location
- Hershey, PA
- Eligibility basics
- Ages 21–35
- RecruitingHealthy volunteersEarly Phase 1
Lorlatinib for Newly-Diagnosed High-Grade Glioma With ROS or ALK Fusion
Nationwide Children's Hospital
- Location
- Cincinnati, OH + 1 other US site
- Eligibility basics
- Ages 1–21
- RecruitingHealthy volunteersPhase 1
Liver Adiposity Effects on Pediatric Statin
Children's Mercy Hospital Kansas City
- Location
- Kansas City, MO
- Eligibility basics
- Ages 8–21
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.