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 volunteersPhase 1
Applying pGz in Mitochondrial Disease
Children's Hospital of Philadelphia
- Location
- Philadelphia, PA
- Eligibility basics
- Ages 10–60
- RecruitingHealthy volunteersPhase 1/Phase 2
ACTION: Trial of Adding Buprenorphine, CBT, and TMS to Improve Outcomes of Long-Term Opioid Therapy for Chronic Pain
Medical University of South Carolina
- Location
- Charleston, SC
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 1/Phase 2
Assess Fibrin in Brains With AD/ADRD
Massachusetts General Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 55–90
- RecruitingHealthy volunteersEarly Phase 1
Role of Autophagy in Type 2 Diabetes Microvascular Dysfunction
Medical College of Wisconsin
- Location
- Milwaukee, WI
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersEarly Phase 1
Predictors of Aspirin Failure in Preeclampsia Prevention
Rockefeller University
- Location
- New York, NY
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Mapping Auricular Vagus Nerve Circuitry
Massachusetts General Hospital
- Location
- Boston, MA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1
Investigating the Persisting Effects of a Single Dose of Psilocybin on Structural Plasticity in Healthy Older Adults
University of California, Berkeley
- Location
- Berkeley, CA
- Eligibility basics
- Ages 60–85
- RecruitingHealthy volunteersPhase 1
Repetitive Transcranial Magnetic Stimulation for Post-concussion Headaches
State University of New York - Upstate Medical University
- Location
- Syracuse, NY
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1
Pilot Study to Identify the Mediators and Inflammatory Cell Surface Receptors Involved in Allergic Airway Inflammation
Benjamin Medoff
- Location
- Boston, MA
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteersPhase 1
Clinical Trial to Evaluate the Safety and Immunogenicity of a Priming Regimen of 426c.Mod.Core-C4b Followed by HxB2.WT.Core-C4b Boosts, Both Adjuvanted With 3M-052 AF + Alum, in Adult Participants Without HIV and in…
National Institute of Allergy and Infectious Diseases (NIAID)
- Location
- Decatur, GA + 1 other US site
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1/Phase 2
Advair HFA in Healthy and HAPE Predisposed Subjects
University of Colorado, Denver
- Location
- Aurora, CO
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteersEarly Phase 1
Vocal Emotion Communication With Cochlear Implants
Father Flanagan's Boys' Home
- Location
- Tempe, AZ + 2 other US sites
- Eligibility basics
- Ages 6–80
- RecruitingHealthy volunteersPhase 1
1726-nm Laser for Acne Inversa (Hidradenitis Suppurativa)
Wynn Medical Center
- Location
- Rosemead, CA
- Eligibility basics
- Ages 18–60
- RecruitingHealthy volunteersEarly Phase 1
Sympathetic Vascular Transduction Across the Menopause Transition: Contributing Mechanisms
University of Missouri-Columbia
- Location
- Columbia, MO
- Eligibility basics
- Ages 18–70 · Women only
- RecruitingHealthy volunteersPhase 1/Phase 2
Dex +/- Caffeine Sedation in a Post-MRI Recovery in a Pediatric Population
University of Chicago
- Location
- Chicago, IL
- Eligibility basics
- Ages 3–12
- RecruitingHealthy volunteersPhase 1
Azithromycin Before Induction
Arrowhead Regional Medical Center
- Location
- Colton, CA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Role of Neural and Hormonal Regulation Factors on Insulin Secretion After Gastric Bypass Surgery
The University of Texas Health Science Center at San Antonio
- Location
- San Antonio, TX + 1 other US site
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersEarly Phase 1
Glucagon-like Peptide 1, Glucose Metabolism and Gastric Bypass
The University of Texas Health Science Center at San Antonio
- Location
- San Antonio, TX + 1 other US site
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersEarly Phase 1
The Effects of Bariatric Surgeries on Glucose Metabolism
The University of Texas Health Science Center at San Antonio
- Location
- San Antonio, TX + 1 other US site
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersEarly Phase 1
Assess Performance Attributes and Acceptability of Non-medicated Intravaginal Rings Among Sexually Active Women in Atlanta, GA
Population Council
- Location
- Atlanta, GA
- Eligibility basics
- Ages 18–49 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Sensitivity of Angiotensin II Type II Receptors in Women Following Preeclampsia
Anna Stanhewicz, PhD
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Comparing Approaches to Assess Nitric Oxide-dependent Cutaneous Vasodilation
University of Iowa
- Location
- Iowa City, IA
- Eligibility basics
- Ages 18–30
- RecruitingHealthy volunteersEarly Phase 1
Acute Progesterone Suppression of Wake vs. Sleep Luteinizing Hormone Pulse Frequency in Pubertal Girls With and Without Hyperandrogenism
University of Virginia
- Location
- Charlottesville, VA
- Eligibility basics
- Ages 10–17 · Women only
- RecruitingHealthy volunteersEarly Phase 1
Hyperandrogenemia and Altered Day-night LH Pulse Patterns
University of Virginia
- Location
- Charlottesville, VA
- Eligibility basics
- Ages 10–17 · Women only
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.