Phase 1 · California
Phase 1 clinical trials in California
262 studies have at least one recruiting site in California. 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.
262 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
Studies
- RecruitingHealthy volunteersPhase 1
A Study of Psychedelics in Healthy Older Adults With Low Well-being
Jennifer Mitchell
- Location
- San Francisco, CA
- Eligibility basics
- Ages 50–85
- RecruitingHealthy volunteersPhase 1
Evaluation of Oral THC and CBD in Men and Women
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 21–55
- RecruitingHealthy volunteersEarly Phase 1
Randomized Directly Observed Therapy Study to Interpret Clinical Trials of Doxy-PEP
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 1
High Potency Cannabis: Acute and Protracted Effects
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 21–55
- RecruitingHealthy volunteersPhase 1
A Study of Safety and Drug Levels of ePGT121v1-LS, PGDM1400LS, and VRC07-523LS in Adult Participants Without HIV-1
National Institute of Allergy and Infectious Diseases (NIAID)
- Location
- San Francisco, CA + 4 other US sites
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1
Dopamine and Sensorimotor Function in Stuttering
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1/Phase 2
A Phase 1/2A, Randomized Study of a T Follicular Helper (TFH)-Targeting Genetic Vaccine Strategy Designed to Induce Broad, Durable Immune Responses
Kara Chew
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 40–64
- 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
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
COES: Curing Order Effects on Sealants
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 5–14
- RecruitingHealthy volunteersEarly Phase 1
Brain Mechanisms Supporting Cannabis-induced Pain Relief
University of California, San Diego
- Location
- La Jolla, CA
- Eligibility basics
- Ages 21–65
- RecruitingHealthy volunteersPhase 1
The Effects of Dietary Supplementation on Serum Protein Glycosylation
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 1
TREAD: Time Restricted Eating Intervention for Alzheimer's Disease
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 60+
- RecruitingHealthy volunteersEarly Phase 1
Multiparametric [18F]F-AraG Imaging in Post-Acute Sequelae of COVID-19 (PASC)
University of California, Davis
- Location
- Sacramento, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 1
Comparative Pharmacokinetics and Pharmacodynamics of Synthetic Nicotine
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 21–65
- RecruitingHealthy volunteersEarly Phase 1
Cannabis Use, Cognition, and the Endocannabinoid System in HIV
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersEarly Phase 1
Mental Health in Veterans and Families After Group Therapies
Soul Medicine Institute
- Location
- Santa Rosa, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersPhase 1/Phase 2
FACE Phase II (a Stage II Trial)
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 60–89
- RecruitingHealthy volunteersEarly Phase 1
Statin Therapy in Primary Sclerosing Cholangitis (PSC): a Multi-omics Study
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersEarly Phase 1
CMV-specific HIV-CAR T Cells as Immunotherapy for HIV/AIDS
City of Hope Medical Center
- Location
- Duarte, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 1
Alternation in the Human Microbiome With Commonly Used Topical Medications
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersEarly Phase 1
Biologic Therapy to Prevent Osteoarthritis After ACL Injury
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–35
- RecruitingHealthy volunteersPhase 1
Age-dependent Effects of Smoked and Oral Delta-9-THC
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1
A Reduced-Intensity Conditioning Regimen (Cyclophosphamide, Pentostatin, Anti-thymocyte Globulin) Followed by Haploidentical Hematopoietic Stem Cell Transplant for the Treatment of Patients With Refractory or Recurrent…
City of Hope Medical Center
- Location
- Duarte, CA
- Eligibility basics
- Up to age 75
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.