Location · California
Clinical trials recruiting in California
1898 recruiting studies have at least one site in California; 701 accept healthy volunteers. Studies that need a specific condition are included too, so check each listing.
Want the research companies that run paid Phase 1 studies for healthy volunteers? Paid clinical trial companies in California.
1,898 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
More recruiting studies (pay not posted)
- RecruitingHealthy volunteers
GBPDC: Gut-Brain in PD Consortium Master Protocol
Duke University
- Location
- Stanford, CA + 3 other US sites
- Eligibility basics
- Ages 21–80
- RecruitingHealthy volunteers
Latinx Children and Surgery
University of California, Irvine
- Location
- Orange, CA
- Eligibility basics
- Ages 2–12
- RecruitingHealthy volunteers
Comparison of Microbiome Changes in Healthy Adults Following Ketone Ester Consumption
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–40
- RecruitingHealthy volunteers
American Lung Association (ALA) Lung Health Cohort
Johns Hopkins University
- Location
- Los Angeles, CA + 26 other US sites
- Eligibility basics
- Ages 25–35
- RecruitingHealthy volunteers
UCLA REST Study (REsearch on Sleep Techniques)
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–22
- RecruitingHealthy volunteers
CHOICE to AVOID or RESIST
Cedars-Sinai Medical Center
- Location
- Beverly Hills, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteers
Predicting Pre-dementia
Prevention Research Consortium Corp.
- Location
- San Diego, CA
- Eligibility basics
- Ages 55+
- RecruitingHealthy volunteers
Supporting Just-In-Time Consent for Prenatal Screening: The INFORM Study
Case Western Reserve University
- Location
- San Francisco, CA + 2 other US sites
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteersPhase 4
Ancillary Nocturnal Urinary Symptoms Analyses for TRIUMPH
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 60+ · Women only
- RecruitingHealthy volunteers
Women Informed to Screen Depending on Measures of Risk (Wisdom Study)
University of California, San Francisco
- Location
- Irvine, CA + 8 other US sites
- Eligibility basics
- Ages 30–74 · Women only
- RecruitingHealthy volunteersPhase 3
Cessation or Reduction of Alcohol Consumption in Veterans: A Randomized Controlled Trial for Alcohol Use Disorder (CRAVE)
VA Office of Research and Development
- Location
- Long Beach, CA + 17 other US sites
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersPhase 3
Delaying the Onset of Nearsightedness Until Treatment (DONUT) Clinical Trial
Ohio State University
- Location
- Berkeley, CA + 11 other US sites
- Eligibility basics
- Ages 6–11
- RecruitingHealthy volunteersPhase 2/Phase 3
Milk Volume Outcomes Following Oral Nicotinamide Riboside Supplementation in Mothers of Extremely Preterm Infants
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Pregnancy and Postpartum Breastfeeding Support for Patients With Gestational Diabetes
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Lung and Heart Function Across Decades of Life in Health
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 24–68
- RecruitingHealthy volunteers
Near Infrared Spectroscopy (NIRS) for Assessment of Depression
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Impact of Peanut Consumption on Stress, Immune Function, Inflammation, and Cardiovascular Health in High-Stress Individuals
USDA, Western Human Nutrition Research Center
- Location
- Davis, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteers
Telehealth Self-Management Coaching Sessions to Improve Quality of Life in Pancreatic Cancer Survivors and Their Family Care Givers
City of Hope Medical Center
- Location
- Duarte, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Medical Residents Learning Weight Management Counseling Skills
University of Massachusetts, Worcester
- Location
- Palo Alto, CA + 6 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Trauma-Informed Care for Smoking Cessation for Pregnancy
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteersPhase 4
The Impact of Dietary Salt on the Severity of Eczema
University of California, San Francisco
- Location
- San Francisco, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Targeting Aging With a Ketone Ester for Function in Frailty
Buck Institute for Research on Aging
- Location
- Novato, CA + 2 other US sites
- Eligibility basics
- Ages 65+
- RecruitingHealthy volunteers
Effectiveness of Brief Intervention in Primary Care for Diverse Young People (Chat)
RAND
- Location
- Commerce, CA + 2 other US sites
- Eligibility basics
- Ages 12–19
- RecruitingHealthy volunteersPhase 4
The Impact of Salt Intake on Sodium in the Skin and Inflammatory Skin Disease
University of California, San Francisco
- Location
- San Francisco, CA + 1 other US site
- Eligibility basics
- Ages 18+