Core: healthy volunteers
Phase 1 clinical trials recruiting now
Phase 1 (and early Phase 1) trials are usually the first time a medicine is studied in people. They are typically small, closely monitored, and many are run in dedicated research units, sometimes with overnight stays.
934 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
Studies
- RecruitingHealthy volunteersEarly Phase 1
Study to Assess Potential Impairments in Estradiol Augmentation of Gonadotropin Secretion in Polycystic Ovary Syndrome
University of Virginia
- Location
- Charlottesville, VA
- Eligibility basics
- Ages 18–30 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Does Spironolactone Normalize Sleep-wake Luteinizing Hormone Pulse Frequency in Pubertal Girls With Hyperandrogenism?
University of Virginia
- Location
- Charlottesville, VA
- Eligibility basics
- Ages 10–17 · Women only
- RecruitingHealthy volunteersPhase 1
PET Detection of CCR2 in Human Atherosclerosis
Washington University School of Medicine
- Location
- St Louis, MO
- Eligibility basics
- Ages 18–89
- RecruitingHealthy volunteersPhase 1/Phase 2
Immunogenicity of Yellow Fever Vaccine 17D in Adults With Prior 17D Vaccination
Oregon Health and Science University
- Location
- Portland, OR
- Eligibility basics
- Ages 20–49
- RecruitingHealthy volunteersEarly Phase 1
Intradermal Influenza Vaccination
Yale University
- Location
- New Haven, CT
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteersPhase 1
Gender Related Differences in the Acute Effects of Delta-9-Tetrahydrocannabinol in Healthy Humans
Yale University
- Location
- West Haven, CT
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1
Gender Related Differences in the Acute Effects of Delta-9-Tetrahydrocannabinol in Healthy Humans: Sub-Study I
Yale University
- Location
- West Haven, CT
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1/Phase 2
Vaginal Microbiome Seeding and Health Outcomes in Cesarean-delivered Neonates.
National Institute of Allergy and Infectious Diseases (NIAID)
- Location
- Falls Church, VA
- Eligibility basics
- Ages 0 mo–50
- RecruitingHealthy volunteersPhase 1
PET Imaging of Radiolabeled Anti-HIV-1 Envelope Monoclonal Antibody (VRC01)
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Reversing Glucose and Lipid-mediated Vascular Dysfunction
University of Kansas Medical Center
- Location
- Kansas City, KS
- Eligibility basics
- Ages 18–79
- RecruitingHealthy volunteersEarly Phase 1
Prenatal Aspirin and Postpartum Vascular Function
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–50 · Women only
- RecruitingHealthy volunteersPhase 1
B-Complex: A Nutraceutical SANS Countermeasure
National Aeronautics and Space Administration (NASA)
- Location
- Houston, TX
- Eligibility basics
- Ages 20–100
- RecruitingHealthy volunteersEarly Phase 1
Metformin for the Treatment of Microvascular Dysfunction After Gestational Diabetes
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersPhase 1
Hyperpolarized 13C-pyruvate Metabolic MRI With Traumatic Brain Injury
University of Maryland, Baltimore
- Location
- Baltimore, MD
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersPhase 1/Phase 2
First-in-Human Evaluation of an Astrocytic Glutamate Transporter (EAAT2) PET Tracer in Dementia
David Wilson
- Location
- San Francisco, CA
- Eligibility basics
- Ages 40–75
- RecruitingHealthy volunteersPhase 1
Increasing Affordable Fruits and Vegetables for Families With Food Insecurity
University of South Carolina
- Location
- Columbia, SC
- Eligibility basics
- Ages 2–10
- RecruitingHealthy volunteersPhase 1/Phase 2
Investigating Whether Acute Elevation of Fatty Acid Levels Alters Cerebral Glucose Transport and Metabolism
University of North Carolina, Chapel Hill
- Location
- Chapel Hill, NC + 1 other US site
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 1
Ondansetron Use for Preventing Pruritus in Patients Undergoing Cesarean Section
Wayne State University
- Location
- Detroit, MI
- Eligibility basics
- Ages 18–50 · Women only
- RecruitingHealthy volunteersPhase 1
Identifying Correlates of Brain Microglial Activation in Neuropsychiatric Syndromes: a Dimensional Approach
The University of Texas Health Science Center, Houston
- Location
- Houston, TX
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersEarly Phase 1
Curcumin and EGCG Supplementation to Improve Serum BDNF and Mood Disturbance
Auburn University
- Location
- Auburn, AL
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteersEarly Phase 1
Gene Expression Changes In Young and Geriatric Skin
Wright State University
- Location
- Fairborn, OH
- Eligibility basics
- Ages 21+
- RecruitingHealthy volunteersPhase 1
Maternal Choline Supplementation and Cannabis Use During Pregnancy: Impact on Early Brain Development
University of Colorado, Denver
- Location
- Aurora, CO
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Type 1 Diabetes, Endothelin, and Skeletal Muscle Mitochondrial Dysfunction: The Role of Sirtuin-1
Augusta University
- Location
- Augusta, GA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 1
Testing Use of Topical Imipramine in Reducing Ultraviolet B Induced Microvesicle Particle Release in Photosensitive Subjects
Wright State University
- Location
- Fairborn, OH
- Eligibility basics
- Ages 18–50
Who these studies look for
Phase 1 studies often have narrow eligibility: specific age and weight ranges, no recent participation in another study, no nicotine, and limits on medications. Some Phase 1 studies recruit patients rather than healthy volunteers, so check each listing.
Matching a page like this one never means you qualify. Each research team decides eligibility at screening.
Questions
Are Phase 1 trials riskier?
Every study carries risk. Phase 1 studies involve less human data about the product, which is why they are closely monitored. The informed consent document explains the known risks; read it carefully and ask questions before signing.
Why do some Phase 1 studies include overnight stays?
Staying in the unit lets staff dose on a precise schedule and collect samples around the clock. Where a record mentions an inpatient stay we flag it on the listing.