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
Spatial Scene Recognition Memory in Epilepsy Surgery
University of California, Davis
- Location
- Sacramento, CA + 1 other US site
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteers
A Study to See if an iPhone Weight Management App Can Help Promote Weight Loss in Adolescents and Young Adults After a Stem Cell Transplant
Jonsson Comprehensive Cancer Center
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 13–30
- RecruitingHealthy volunteers
New Approach to Objectively Measure Social Engagement in Older Adults With Hearing Loss
University of Southern California
- Location
- Los Angeles, CA + 1 other US site
- Eligibility basics
- Ages 60+
- RecruitingHealthy volunteers
A Culturally Informed Patient Navigation Program (CFPN) to Reduce Delays Between Diagnosis and Treatment in American Indian and Alaska Native Cancer Patients Living in Rural California
University of Southern California
- Location
- Bishop, CA + 1 other US site
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Wayfinding Intervention and Long-Term Memory
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 60–85
- RecruitingHealthy volunteers
Positive Affect Treatment for Adolescents With Early Life Adversity
University of California, Irvine
- Location
- Irvine, CA
- Eligibility basics
- Ages 12–16
- RecruitingHealthy volunteers
Intermittent Fasting on Body Fat and Quality of Life
Loma Linda University
- Location
- Loma Linda, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 4
Regional Blocks for Lateral Condyle Fractures
University of California, Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 4–12
- RecruitingHealthy volunteers
Telemedicine to Support Living Kidney Donor Candidates
University of California, Irvine
- Location
- Orange, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Clinical and Biological Characteristics of Hidradenitis Suppurativa
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 13+
- RecruitingHealthy volunteers
LPFC Organization in Emotion-Duration Difference Estimation
University of California, Santa Barbara
- Location
- Santa Barbara, CA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteersPhase 2
Regulation of Affect and Physiology in Depression
University of Southern California
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18–27
- RecruitingHealthy volunteers
The Use of Lymph Node Biopsies to Support HIV Pathogenesis Studies
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–70
- RecruitingHealthy volunteersPhase 2
Effects of Cannabidiol and Tetrahydrocannabinol on Microbiome and Neuroinflammation in HIV
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 21–70
- RecruitingHealthy volunteers
Women Focused Encounters for Resilience Independence Strength and Eudaimonia
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Implementing Scalable, PAtient-centered, Team-based, Technology-enabled Care for Adults With Type 2 Diabetes (iPATH)
Stanford University
- Location
- Stanford, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Avoidance-driven Decision Making and Learning in Anorexia Nervosa and Bulimia Nervosa
University of California, San Diego
- Location
- La Jolla, CA
- Eligibility basics
- Ages 18–39 · Women only
- RecruitingHealthy volunteers
ACT Group for Family Caregivers of Stroke Survivors
The Wright Institute
- Location
- Alameda, CA
- Eligibility basics
- Ages 40+
- RecruitingHealthy volunteers
Bridge the Gap (BTG) - Black Youth Group
Children's Hospital Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 12–17
- RecruitingHealthy volunteers
Protocol for Collecting, Banking and Distributing Human Tissue Samples: St. Jude Children's Research Hospital Tissue Resources Core Facility
St. Jude Children's Research Hospital
- Location
- Palo Alto, CA + 12 other US sites
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Individual Cerebral Hemodynamic Oxygenation Relationships (ICHOR 1)
Children's Hospital Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Up to age 18
- RecruitingHealthy volunteers
Engaging Mental Effort: Process- and Person-Based Reward Experiences, Effort Reinforcement Intervention, and Cascading Effects on Challenging Tasks
University of California, Davis
- Location
- Davis, CA
- Eligibility basics
- Ages 9–13
- RecruitingHealthy volunteers
Incentive Processing and Learning in Anorexia Nervosa and Bulimia Nervosa
University of California, San Diego
- Location
- La Jolla, CA
- Eligibility basics
- Ages 18–39 · Women only
- RecruitingHealthy volunteers
Fall Risk Assessment and Speech Intelligibility Enhancement Using In-ear Device
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 55+