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
Effect of Watermelon on Cardiometabolic Health
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Any age listed · Women only
- RecruitingHealthy volunteers
The Effects of Very Brief Exposure on PTSD in U.S. Combat Veterans
Children's Hospital Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteers
PPMI Clinical - Establishing a Deeply Phenotyped PD Cohort
Michael J. Fox Foundation for Parkinson's Research
- Location
- La Jolla, CA + 29 other US sites
- Eligibility basics
- Ages 30+
- RecruitingHealthy volunteersPhase 2/Phase 3
A Study of Potential Disease Modifying Treatments in Individuals at Risk for or With a Type of Early Onset AD Caused by a Genetic Mutation
Washington University School of Medicine
- Location
- La Jolla, CA + 11 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 2/Phase 3
A Study of a Potential Disease Modifying Treatment in Individuals at Risk for or With a Type of Early Onset AD Caused by a Genetic Mutation
Washington University School of Medicine
- Location
- La Jolla, CA + 11 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Effect of Daily Mixed Spice Consumption on Memory Function
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 50–80
- RecruitingHealthy volunteers
Social Media Influences on Engagement and Susceptibility to Non-combustible Tobacco Product Use Among Youth and Young Adults (AYA)
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 14–17
- RecruitingHealthy volunteers
Pancreatic Cancer Early Detection Consortium
Arbor Research Collaborative for Health
- Location
- Burbank, CA + 39 other US sites
- Eligibility basics
- Ages 18–90
- RecruitingHealthy volunteers
Tactile Pre-Visit Imagery
University of Southern California
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 4–10
- RecruitingHealthy volunteers
Improving Overactive Bladder Treatment Access and Adherence
Stanford University
- Location
- Redwood City, CA
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Web-based Program to Improve Self-management Among Veterans-caregiver Dyads
VA Office of Research and Development
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 2
Fimepinostat, Combination HDAC and Pi3-kinase Inhibitor Tumor-Directed Therapy for Cushing Disease
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Deep Functional Phenotyping of the ALA Lung Health Cohort
Johns Hopkins University
- Location
- Los Angeles, CA + 11 other US sites
- Eligibility basics
- Ages 25–35
- RecruitingHealthy volunteers
Effects of Goji vs. Fiber on Macular Degeneration
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 65–95
- RecruitingHealthy volunteers
Comprehensive HHT Outcomes Registry of the United States (CHORUS)
Cure HHT
- Location
- Los Angeles, CA + 15 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Social Media Support Groups for Adolescent Vaping Cessation
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 13+
- RecruitingHealthy volunteers
Social Facilitation of Emotion Regulation in Adolescence
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 13–25
- RecruitingHealthy volunteers
Health-E You Efficacy Trial for Male Adolescents
Johns Hopkins University
- Location
- Oakland, CA + 7 other US sites
- Eligibility basics
- Ages 13–21 · Men only
- RecruitingHealthy volunteers
Sodium in the Skin and Atopic Dermatitis
University of California, San Francisco
- Location
- San Francisco, CA + 1 other US site
- Eligibility basics
- Ages 50+
- RecruitingHealthy volunteers
Cultural Adaptation of Drug Treatment for DJJ Youth
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 13–17
- RecruitingHealthy volunteers
Brain/Craving Response to Smoking Cues After Oral Nicotine Pouch Use
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 21–55
- RecruitingHealthy volunteers
Sexual Health Advocacy for Guys - a Text Messaging-based HIV Prevention Program for Guys Who Are Into Guys
Center for Innovative Public Health Research
- Location
- San Clemente, CA
- Eligibility basics
- Ages 13–22 · Men only
- RecruitingHealthy volunteers
Abuse Liability and Appeal of Oral Nicotine Products
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 21–25
- RecruitingHealthy volunteers
Improving Behavioral Health for Caregivers and Children After Pediatric Injury
Medical University of South Carolina
- Location
- Los Angeles, CA + 3 other US sites
- Eligibility basics
- Ages 18+