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
Mango Intake and Gut and Cardiometabolic Health in Hispanic/Latino Adolescents
University of California, Davis
- Location
- Davis, CA
- Eligibility basics
- Ages 12–19
- RecruitingHealthy volunteers
Montalcino Aortic Consortium: Precision Medicine for Heritable Thoracic Aortic Disease
The University of Texas Health Science Center, Houston
- Location
- Newport Beach, CA + 12 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Effects of Mango or Low-Fat Cookie Consumption on Gut Health, and Its Relationship With Mental, Sexual and Skin Health
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteers
Role of Transposable Elements in Septic Immune Aging
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Defense and Veterans Center for Integrative Pain Management (DVCIPM) Pain Registry Biobank
Defense and Veterans Center for Integrative Pain Management
- Location
- San Diego, CA + 1 other US site
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteers
Pilot Trial of Fetoscopic Endoluminal Tracheal Occlusion (FETO) in Severe Left Congenital Diaphragmatic Hernia (CDH)
Hanmin Lee
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Behavioral Weight Loss Intervention Utilizing Mobile Health Technology in Hematopoietic Stem Cell Transplant Patients
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 13–30
- RecruitingHealthy volunteers
Efficacy of Repeated Low-level Red-light Therapy in Myopia Control
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 8–13
- RecruitingHealthy volunteers
Effects of Sabroxy® Supplementation on Insulin Resistance and Cognitive Function in Adults With Mild Cognitive Impairment and Insulin Resistance
SF Research Institute, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 40–80
- RecruitingHealthy volunteers
Patient-centered Information on Permanent Contraception
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 21–45 · Women only
- RecruitingHealthy volunteersPhase 3
Biomarker Exploration in Aging, Cognition and Neurodegeneration
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Ages 60+
- RecruitingHealthy volunteers
Wavefront-guided LASIK Surgery Compared to Ray Tracing-Guided LASIK Surgery
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 22–59
- RecruitingHealthy volunteers
Effects of Mixed Nut Consumption on Satiety and Weight Management
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteers
Effects of Watermelon Juice on Heart Rate Recovery and Post-exercise Muscle Soreness
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 21–50
- RecruitingHealthy volunteers
Effects of Fresh Watermelon Consumption on Satiety and Cardiometabolic Health
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteers
Effects of Snack Types on Acute Glucose and Insulin Response
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteers
Effects of Fresh Mango Pulp Consumption on Satiety and Cardiometabolic Health
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteers
Effects of Watermelon Consumption on Satiety and Digestive Health
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 10–55
- RecruitingHealthy volunteersPhase 2
This Study is Assessing the Safety and Efficacy of Immune Inhibition as a Treatment to Prevent Primary Graft Dysfunction
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
@neurIST : Intregrated Biomedical Informatics for the Management of Cerebral Aneurysms
University Hospital, Geneva
- Location
- San Francisco, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL) Study
University of Wisconsin, Madison
- Location
- Los Angeles, CA + 9 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 4
Androgen Effects on the Reproductive Neuroendocrine Axis, 2025 Version
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–35 · Women only
- RecruitingHealthy volunteersPhase 3
Geriatric Evaluation and Management With Survivorship Health Education for Older Survivors of Cancer, GEM-S Trial
University of Rochester
- Location
- Fremont, CA + 43 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 2
Understanding the Clinical Pharmacology of Marijuana-Tobacco Co-administration
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 21–65