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.
933 recruiting studiesSource: ClinicalTrials.gov, refreshed October 28, 2026How we list studies
Studies
- RecruitingHealthy volunteersEarly Phase 1
Role of ET-1, Physical Activity, and Sedentary Behavior in Microvascular Dysfunction Following GDM
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–50 · Women only
- 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
Pharmacogenetics of Response to GLP1R Agonists
University of Maryland, Baltimore
- Location
- Lancaster, PA
- Eligibility basics
- Ages 18–89
- RecruitingHealthy volunteersPhase 1
A Phase 1 Study of 99mTc-p5+14 in Healthy Volunteers and Patients With AL or ATTR Systemic Amyloidosis
University of Tennessee Graduate School of Medicine
- Location
- Knoxville, TN
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 1
Mifepristone vs Misoprostol
Montefiore Medical Center
- Location
- The Bronx, NY
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersPhase 1/Phase 2
Effects of Psilocybin on Electrophysiology and the Dynamic Content of Thought
Johns Hopkins University
- Location
- Baltimore, MD
- Eligibility basics
- Ages 18–75
- RecruitingHealthy volunteersPhase 1
Blackcurrants Modify Gut Microbiota and Reduce Osteoporosis Risk in Postmenopausal Females
University of Connecticut
- Location
- Storrs, CT
- Eligibility basics
- Ages 45–70 · Women only
- RecruitingHealthy volunteersPhase 1/Phase 2
Hyperemesis Gravidarum Risk Reduction With Metformin
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–49 · Women only
- RecruitingHealthy volunteersPhase 1
Safety, Tolerability, and Bioeffects of Alirocumab in Non-treatment Seeking Heavy Drinkers
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
- Location
- Bethesda, MD
- Eligibility basics
- Ages 21–65
- RecruitingHealthy volunteersEarly Phase 1
PK/PD of Oral and Vaporized Delta-9-Tetrahydrocannabinol (THC) in Older Adults
Yale University
- Location
- West Haven, CT
- Eligibility basics
- Ages 65+
- RecruitingHealthy volunteersPhase 1
Thymalfasin (Thymosin Alpha 1; Ta1) as an Enhancer of Vaccine Response Among Older Adults Receiving Booster Doses of COVID-19 Vaccine
The Methodist Hospital Research Institute
- Location
- Houston, TX
- Eligibility basics
- Ages 65–100
- RecruitingHealthy volunteersEarly Phase 1
Restructuring the Alpha-Gamma Code in Aging Vision
Boston University Charles River Campus
- Location
- Boston, MA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Evaluation of the Electronic Cigarette Withdrawal Syndrome
Johns Hopkins University
- Location
- Baltimore, MD
- Eligibility basics
- Ages 21–55
- RecruitingHealthy volunteersEarly Phase 1
Assistance Delivery and Muscle Coordination
The Catholic University of America
- Location
- Washington D.C., DC
- Eligibility basics
- Ages 20–80
- RecruitingHealthy volunteersEarly Phase 1
Mechanistic Studies of Psilocybin in Headache Disorders
Yale University
- Location
- West Haven, CT
- Eligibility basics
- Ages 21–70
- RecruitingHealthy volunteersEarly Phase 1
Optic Nerve Head Strain in Non-glaucoma Subjects
Johns Hopkins University
- Location
- Baltimore, MD
- Eligibility basics
- Ages 30–90
- RecruitingHealthy volunteersPhase 1
Cabotegravir-Hormone PK/PD Interactions for HIV Prevention
Johns Hopkins University
- Location
- Baltimore, MD
- Eligibility basics
- Ages 19+
- RecruitingHealthy volunteersPhase 1
Investigating the Mechanisms of the Effects of Psilocybin on Visual Perception and Visual Representations in the Brain
University of California, Berkeley
- Location
- Berkeley, CA
- Eligibility basics
- Ages 21+
- RecruitingHealthy volunteersPhase 1/Phase 2
Vasopressin and Pain Perception in the Brain
University of Maryland, Baltimore
- Location
- Baltimore, MD
- Eligibility basics
- Ages 18–65
- 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
JIT: Effect of Pain on DT in TMD
University of Minnesota
- Location
- Minneapolis, MN
- Eligibility basics
- Ages 21–65
- RecruitingHealthy volunteersEarly Phase 1
Zynrelef vs Exparel: The Battle of Postoperative Pain Control After Robotic Sleeve Gastrectomy
Texas Tech University Health Sciences Center
- Location
- Lubbock, TX
- Eligibility basics
- Ages 18–65
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.