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 volunteersPhase 3
Aspirin Dose Escalation for the Prevention of Recurrent Preterm Delivery Trial
The George Washington University Biostatistics Center
- Location
- San Francisco, CA + 13 other US sites
- Eligibility basics
- Ages 14+ · Women only
- RecruitingHealthy volunteers
DILIN - Prospective Study
Duke University
- Location
- Los Angeles, CA + 5 other US sites
- Eligibility basics
- Ages 2+
- RecruitingHealthy volunteers
Genomic Sequencing in Anatomically Normal Fetuses
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–64
- RecruitingHealthy volunteers
California MEPS Hub
University of California, Los Angeles
- Location
- Oakland, CA + 2 other US sites
- Eligibility basics
- Ages 18–59 · Men only
- RecruitingHealthy volunteers
Collection of Immunology Specimens From Patients With Cancer or Blood Disorders, and Healthy Volunteers
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 19+
- RecruitingHealthy volunteers
Kimchi and Gut Health
University of California, Davis
- Location
- Davis, CA + 1 other US site
- Eligibility basics
- Ages 19–70
- RecruitingHealthy volunteers
BID WM Digital Intervention in Aging
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 60–85
- RecruitingHealthy volunteers
Study of Food Aversion in Patients With Anorexia Nervosa
University of California, San Diego
- Location
- La Jolla, CA
- Eligibility basics
- Ages 18–55 · Women only
- RecruitingHealthy volunteersPhase 2
SAMe Trial for Patients With Alcoholic Cirrhosis
Indiana University
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 18–70
- RecruitingHealthy volunteersPhase 3
Evaluating Whether an Educational Website Called Current Together After Cancer (CTAC) Improves Follow-up Care for Colorectal Cancer Survivors
SWOG Cancer Research Network
- Location
- Arroyo Grande, CA + 374 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Effects of Brain Stimulation on Cognition, Oscillations and GABA Levels in Schizophrenia
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18–47
- RecruitingHealthy volunteers
Pneumatic Compression vs Blood Flow Restriction for Muscle Recovery
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–30
- RecruitingHealthy volunteers
My Life and My Experiences Project
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Ages 12–18
- RecruitingHealthy volunteers
Continuous Glucose Monitoring (CGM) in Prediabetes With Community Based Recruitment
David S Black, PhD
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 35+
- RecruitingHealthy volunteersPhase 2
Trial of Suvorexant for Sleep in Children With Autism
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 13–17
- RecruitingHealthy volunteers
Behavior and Risk Awareness Through Video Education for Firefighters
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Examining the Role of Female Endogenous Sex Hormones in Eccentric Exercise
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–35 · Women only
- RecruitingHealthy volunteers
Neonatal Platelet Transfusion Threshold Trial
NICHD Neonatal Research Network
- Location
- Palo Alto, CA + 19 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Moon and Sun Brothers: A Community Prevention Intervention (Hermanos de Luna y Sol)
San Francisco State University
- Location
- San Francisco, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Pituitary Tumor Surveillance: Pathogenic Correlation
Cedars-Sinai Medical Center
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Understanding Immunity to the Flu Vaccine in COVID-19 Patients
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 9–64
- RecruitingHealthy volunteersPhase 2/Phase 3
Single Nuclei RNA-seq to Map Adipose Cellular Populations and Senescent Cells in Older Subjects
Cedars-Sinai Medical Center
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Access to Genetic Testing in Underserved Patients With Cancer
University of Southern California
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
The THRIVE Study: Teaching Healthy Regulation in Individuals & Vulnerable Environments
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Ages 11–14