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 Ashwagandha Root Extract on Stress, Anxiety, and Sleep Quality in Adults Experiencing Minority Stress
SF Research Institute, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Efficacy and Safety of Shatavari Root Extract in Women's Sexual Wellness
SF Research Institute, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 20–50 · Women only
- RecruitingHealthy volunteers
Pregnancy and Developmental Outcomes After Transfer of Reportedly Aneuploid or Mosaic Embryos
Stanford University
- Location
- Sunnyvale, CA
- Eligibility basics
- Ages 18–55 · Women only
- RecruitingHealthy volunteers
Strain-Counterstrain Treatment of Piriformis Pain
Loma Linda University
- Location
- Loma Linda, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 2
Examining Mu Opioid Mechanisms of Ketamine's Rapid Effects in OCD (MKET2)
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteers
Mechanistic Insights From Bronchoscopy Airway Samples
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–70
- RecruitingHealthy volunteers
Ketogenic Diet and Brain Response in Anorexia Nervosa
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 3
Local Bisphosphonate Effect on Recurrence Rate in Extremity Giant Cell Tumor of Bone
St. Louis University
- Location
- Los Angeles, CA + 10 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Brief Behavioral Treatment for Insomnia in Veterans With Posttraumatic Stress Disorder
VA Office of Research and Development
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–75
- RecruitingHealthy volunteers
Hybrid Effectiveness-Implementation Trial of an Executive Functioning Intervention for Children's Mental Health Services
San Diego State University
- Location
- San Diego, CA + 1 other US site
- Eligibility basics
- Ages 6–99
- RecruitingHealthy volunteersPhase 4
Normal-weight Diabetes: Adipocyte-directed Therapy With Pioglitazone or Tirzepatide
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 30–70
- RecruitingHealthy volunteers
Mediators and Moderators of Auditory Training
Northeastern University
- Location
- Riverside, CA + 2 other US sites
- Eligibility basics
- Ages 18–85
- RecruitingHealthy volunteersPhase 2
Sleep Health in U.S. Marines
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Insomnia Treatment and Cardiometabolic Health in Older Adults With Posttraumatic Stress Disorder
University of California, Los Angeles
- Location
- North Hills, CA
- Eligibility basics
- Ages 50+
- RecruitingHealthy volunteers
Development, Attention, and Inhibition Study
University of California, Davis
- Location
- Davis, CA
- Eligibility basics
- Ages 4–7
- RecruitingHealthy volunteers
Comparing Hearing Aid Fitting Methods in Blast-exposed Veterans
VA Office of Research and Development
- Location
- Loma Linda, CA
- Eligibility basics
- Ages 18–60
- RecruitingHealthy volunteers
Role of Angiogenesis in Dermatologic Diseases: A Potential Therapeutic Target
University of California, Irvine
- Location
- Irvine, CA + 1 other US site
- Eligibility basics
- Ages 16+
- RecruitingHealthy volunteers
Collection of Blood for Multiple Collaborative Studies
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Early Intervention to Promote Cardiovascular Health of Mothers and Children
JHSPH Center for Clinical Trials
- Location
- San Luis Obispo, CA + 8 other US sites
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Prebiotic Effects of California Grapes on Gut Health and Cardiometabolic Health in Overweight Men and Women
University of California, Davis
- Location
- Davis, CA
- Eligibility basics
- Ages 45–70
- RecruitingHealthy volunteers
Optimizing Liver MRI Using Breath-Holding With and Without Oxygen
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–75
- RecruitingHealthy volunteers
A Global Study of the PETAL Consortium
Massachusetts General Hospital
- Location
- Duarte, CA + 9 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 3
Azithromycin Prophylaxis for PRElabor CEsarean DElivery Trial
The George Washington University Biostatistics Center
- Location
- San Francisco, CA + 13 other US sites
- Eligibility basics
- Any age listed · Women only
- RecruitingHealthy volunteers
Establishing Walking-related Digital Biomarkers in Rare Childhood Onset Progressive Neuromuscular Disorders
Columbia University
- Location
- Palo Alto, CA + 2 other US sites
- Eligibility basics
- Ages 5+