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
Inflammation, Diabetes, Ethnicity and Obesity Cohort
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–75
- RecruitingHealthy volunteers
Parkinson Progression Marker Initiative Online (PPMI Online)
Michael J. Fox Foundation for Parkinson's Research
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Effects of Dietary Supplements on Muscle Mass and Function While Using GLP-1 Medication
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Engaging Diverse and Underserved Communities in Cancer Awareness Training and Education
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteers
Quality of End-of-Life Care for Children With Cancer
Children's Oncology Group
- Location
- Oakland, CA + 27 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
A Clinic-wide Intervention (Primary Care-GI Connect) for Improving Rates of Colonoscopy After Abnormal Fecal Immunochemical Test Result in Patients at Federally Qualified Health Centers
Jonsson Comprehensive Cancer Center
- Location
- Los Angeles, CA
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Assessing Brain Metabolism Using MRS With Deuterated Glucose
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
A Multi-Modality Surveillance Program for Women at High Risk for Breast Cancer
University of Chicago
- Location
- La Jolla, CA + 2 other US sites
- Eligibility basics
- Ages 25+ · Women only
- RecruitingHealthy volunteersPhase 4
Pragmatic Evaluation of Events And Benefits of Lipid-lowering in Older Adults
Duke University
- Location
- Fresno, CA + 88 other US sites
- Eligibility basics
- Ages 75+
- RecruitingHealthy volunteers
Friedreich Ataxia Global Clinical Consortium UNIFIED Natural History Study
Friedreich's Ataxia Research Alliance
- Location
- Los Angeles, CA + 8 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
UCSF Center for Genome Surgery Biobank and Registry
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Pilot Study on In-vivo Non-invasive Skin Imaging Using Multiphoton Microscopy
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Intracranial Neurophysiological Signatures of Fear and Anxiety in Humans
Duke University
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 18–70
- RecruitingHealthy volunteers
Shoulder Strength in Baseball Players
Loma Linda University
- Location
- Loma Linda, CA
- Eligibility basics
- Ages 15–22
- RecruitingHealthy volunteers
Effects of Watermelon or Low-fat Cookie Consumption on Wellness
San Diego State University
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–50
- RecruitingHealthy volunteersPhase 3
Digital Health Intervention for Self-Management and Telemonitoring in Chimeric Antigen Receptor (CAR-T) Therapy
City of Hope Medical Center
- Location
- Duarte, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Diet Quality Pilot Intervention in LA Safety Net
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
The HOPE Biobank Resource (BMT CTN 2402 HOPE)
Medical College of Wisconsin
- Location
- Duarte, CA + 13 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
The SEQUENCE Trial
Northwestern University
- Location
- Sacramento, CA + 4 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Enhancing Attention and Wellbeing Using Digital Therapeutics
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 60–99
- RecruitingHealthy volunteers
ASSESS ALL ALS Study
St. Joseph's Hospital and Medical Center, Phoenix
- Location
- Irvine, CA + 35 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
PREVENT ALL ALS Study
St. Joseph's Hospital and Medical Center, Phoenix
- Location
- La Jolla, CA + 30 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Human-Created vs AI-generated Art on Immediate Psychological Responses
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Coronary Atherosclerosis T1-Weighted Characterization (CATCH)
Cedars-Sinai Medical Center
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+