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
Impact of Lactation Antenatal Teaching by Clinicians and Healthcare Providers
Loma Linda University
- Location
- Loma Linda, CA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteers
Cognitive and Electrophysiological Assessment of Non-Invasive Temporally-Interfering Electric Fields Stimulation (TIEFS)
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteers
A Dyadic Sleep Health Approach for Persons With Alzheimer's Disease and Caregivers
University of California, Los Angeles
- Location
- La Jolla, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Dynamic Critical Congenital Heart Screening With Addition of Perfusion Measurements
University of California, Davis
- Location
- Davis, CA
- Eligibility basics
- Up to age 1 mo
- RecruitingHealthy volunteersPhase 4
Investigation of Locus Coeruleus Function in Sustained Attention
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18–60
- RecruitingHealthy volunteers
Childhood Cancer Survivor Study
St. Jude Children's Research Hospital
- Location
- Duarte, CA + 26 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Behavioral Activation and Risk Reduction for Stimulant Use Among Sexually Active Adolescents and Young Adults
Westat
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 16–24
- RecruitingHealthy volunteers
Melanin and Dermal Uptake of Thirdhand Cigarette Smoke
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteers
Measuring Environmental Tobacco and Cannabis: Pollutants and Exposures
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 21–50
- RecruitingHealthy volunteersPhase 4
Computational Assessment of GABA Receptor Modulation in PTSD
VA Office of Research and Development
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 4
Tranexamic Acid for Second Trimester Dilation and Evacuation and Bleeding Outcomes
University of California, San Diego
- Location
- San Diego, CA + 2 other US sites
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Multivitamin and Mineral Supplementation and Healthy Aging
University of California, San Diego
- Location
- La Jolla, CA
- Eligibility basics
- Ages 40–60
- RecruitingHealthy volunteers
Acoustic and Electrical Stimulation for the Treatment of Tinnitus
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Platelet Expression of FcγRIIa and Arterial Hemodynamics to Predict Recurrent Stroke in Intracranial Atherosclerosis
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 30+
- RecruitingHealthy volunteers
Polyphenols and Cognitive Decline
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 50+
- RecruitingHealthy volunteers
Refitting Satisfied INFUSE One-Day Multifocal Wearers to DAILIES TOTAL1 Multifocal Contact Lenses
Gordon Schanzlin New Vision
- Location
- La Jolla, CA
- Eligibility basics
- Ages 40+
- RecruitingHealthy volunteers
Village-Integrated Eye Worker Trial II
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 60+
- RecruitingHealthy volunteers
Building Resilient Families
Loma Linda University
- Location
- Loma Linda, CA
- Eligibility basics
- Ages 3–11
- RecruitingHealthy volunteersPhase 2/Phase 3
Naltrexone for Overdose Prevention
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Increasing Germline Genetic Testing for Patients With Cancer
Josh Peterson
- Location
- Los Angeles, CA + 9 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Implementation Supports to Reduce Burnout in Therapists Delivering Child Trauma EBPs
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 3–99
- RecruitingHealthy volunteers
fNIRS for Disorders of Consciousness
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 2
Hyperpolarized Carbon Metabolic Imaging in Multiple Sclerosis
Ari Green
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Retinal Imaging in Patients With Inherited Retinal Degenerations
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 13+