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
Researching Economical Adjuvants to Cancer Therapy
Florida State University
- Location
- Tallahassee, FL
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersEarly Phase 1
Diffusion MRI in Heart Failure
Massachusetts General Hospital
- Location
- Charlestown, MA
- Eligibility basics
- Ages 18–85
- RecruitingHealthy volunteersEarly Phase 1
PET Imaging Evaluation of [11C]SY08
Massachusetts General Hospital
- Location
- Charlestown, MA
- Eligibility basics
- Ages 50–80
- RecruitingHealthy volunteersEarly Phase 1
Precision Dosing of Metformin in Youth With T2D
University of California, San Francisco
- Location
- Oakland, CA + 1 other US site
- Eligibility basics
- Ages 10–21
- RecruitingHealthy volunteersEarly Phase 1
Cardiometabolic Benefit of Reducing Iatrogenic Hyperinsulinemia Using Insulin Adjunctive Therapy in Type 1 Diabetes
Vanderbilt University Medical Center
- Location
- Nashville, TN
- Eligibility basics
- Ages 18–60
- RecruitingHealthy volunteersEarly Phase 1
RM1 Project 1 - tAN Naloxone
Medical University of South Carolina
- Location
- Charleston, SC
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1
THC and CBD: A Controlled Human Study Probing a Harm Reduction Strategy
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 21–55
- RecruitingHealthy volunteersPhase 1
The Impact of Gestational Diabetes Mellitus on Cerebral Blood Flow and Cerebrovascular Function After Pregnancy
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–50 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Sex Differences in the Vascular Effects of E-cigarette Use
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–24
- RecruitingHealthy volunteersEarly Phase 1
Role of Inflammation in Vascular Phenotype Associated With E-cigarette Use
University of Iowa
- Location
- Iowa City, IA + 1 other US site
- Eligibility basics
- Ages 18–24
- RecruitingHealthy volunteersPhase 1/Phase 2
Treatment of Relapsed/Refractory Intracranial Glioma in Patients Under 22 Years of Age
University of Miami
- Location
- Miami, FL
- Eligibility basics
- Ages 1–21
- RecruitingHealthy volunteersEarly Phase 1
Positron Emission Tomography (PET) Imaging of Cholesterol Trafficking: Clinical Evaluation of [18F]FNP-59 in Normal Human Subjects (Group 1)
Benjamin Viglianti
- Location
- Ann Arbor, MI
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Positron Emission Tomography (PET) Imaging of Cholesterol Trafficking: Clinical Evaluation of [18F]FNP-59 in Normal Human Subjects (Groups 2, 3 & 4)
Benjamin Viglianti
- Location
- Ann Arbor, MI
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Metformin and Muscle Recovery
University of Utah
- Location
- Salt Lake City, UT
- Eligibility basics
- Ages 60+
- RecruitingHealthy volunteersPhase 1
S-Nitrosylation (SNO) Therapy During Autologous Blood Transfusion
James Reynolds
- Location
- Cleveland, OH
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteersEarly Phase 1
An fMRI Investigation of the Effects of IV Lidocaine on Tinnitus
D. Bradley Welling, MD, PhD
- Location
- Boston, MA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Understanding Disorder-specific Neural Pathophysiology in Laryngeal Dystonia and Voice Tremor
Massachusetts Eye and Ear Infirmary
- Location
- Boston, MA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersPhase 1
Delayed Immunological Tolerance in Patients With Well-functioning Pre-existing HLA-matched Kidney Transplants
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Trigeminal Evoked Responses to Improve Rhizotomy
University of Minnesota
- Location
- Minneapolis, MN
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Early Neurovascular Adaptations in Aging Women
University of Missouri-Columbia
- Location
- Columbia, MO
- Eligibility basics
- Ages 18–70 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Study of Biodistribution, Metabolism, Excretion and Brain Uptake of 11C-HY-2-15
University of Pennsylvania
- Location
- Philadelphia, PA
- Eligibility basics
- Ages 40–80
- RecruitingHealthy volunteersEarly Phase 1
Bone Marrow Derived Stem Cells Mobilization for Treatment of Abnormal Endometrium
Hugh Taylor
- Location
- Orange, CT
- Eligibility basics
- Ages 18–40 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Differing Levels of Hypoglycemia
University of Maryland, Baltimore
- Location
- Baltimore, MD
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1
Cannabidiol (CBD) in Adults With ASD
Johns Hopkins University
- Location
- Baltimore, MD
- Eligibility basics
- Ages 18+
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.