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
Diagnosing Obstructive Sleep Apnea Using Electromyography of the Muscles of the Mouth
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteers
Huntington's Disease Biobank: Advancing Remote Monitoring and Deep Phenotyping
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Any age listed
- RecruitingHealthy volunteers
Clinical Translation of a Novel Brain PET Insert for Simultaneous PET/MR
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 21+
- RecruitingHealthy volunteers
Multi-Omics for Maternal Health After Preeclampsia
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18–50 · Women only
- RecruitingHealthy volunteers
Microbiome Sampling During Endurance Exercise
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteers
Babies' Brain Responses to Strangers
University of California Santa Cruz
- Location
- Santa Cruz, CA
- Eligibility basics
- Ages 7 mo–1
- RecruitingHealthy volunteers
TREAT-BE Study (Treatment With Resection and Endoscopic Ablation Techniques for Barrett's Esophagus)
University of Colorado, Denver
- Location
- Los Angeles, CA + 3 other US sites
- Eligibility basics
- Ages 18–100
- RecruitingHealthy volunteers
Smoke-free Home Study in Subsidized Housing
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 3
Comparative Effectiveness of MRgFUS Versus CTgRFA for Osteoid Osteomas
Matthew Bucknor
- Location
- Palo Alto, CA + 2 other US sites
- Eligibility basics
- Ages 8+
- RecruitingHealthy volunteers
Researchers At UC San Diego Are Learning About the Benefits of Human Milk and How It Influences Infant and Child Health
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18+ · Women only
- RecruitingHealthy volunteers
Clinical Validation of the Role of microRNA Binding Site Mutations in Cancer Risk, Prevention and Treatment
MiraKind
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
The Healthy Elderly Longevity Cohort
Scripps Translational Science Institute
- Location
- La Jolla, CA
- Eligibility basics
- Ages 80+
- RecruitingHealthy volunteers
CYP2C19 Variants and Limonene Metabolism
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Improving Psychological and Vestibular Health: MINDGAPS
University of Montana
- Location
- San Diego, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Role of Nutrient Transit in Hyperinsulinemic Hypoglycemia
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Longitudinal Multi-Omic Profiles to Reveal Mechanisms of Obesity-Mediated Insulin Resistance
Stanford University
- Location
- Stanford, CA
- Eligibility basics
- Ages 35–65
- RecruitingHealthy volunteers
Obesity, Insulin Resistance, and PASC: Persistent SARS-CoV-2
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 18–80
- RecruitingHealthy volunteersPhase 2
Tirzepatide: Reversal of Lipotoxicity and Adipose Tissue Dysfunction in Humans With Overweight/Obesity
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 18–70
- RecruitingHealthy volunteers
Beneficial Exposome Study
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Efficacy and Safety of a Proprietary Blend of Ashwagandha Root Extract (Aqueous) in Adult Men and Women With High Stress and Anxiety: A Randomized, Double-blind, Three-arm, Parallel, Placebo-controlled Study
SF Research Institute, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteers
Efficacy and Safety of Shatavari for Treatment of Menopausal Symptoms in Women: A Randomized, Double-blind, Three-arm, Parallel, Placebo-controlled Study
SF Research Institute, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 45–55 · Women only
- RecruitingHealthy volunteersPhase 4
Iron Deficiency Anemia (IDA) and the Brain
Children's Hospital Los Angeles
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 16–60 · Women only
- RecruitingHealthy volunteers
An Evaluation of LASIK, SMILE and PRK Surgery in Physicians
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 21–62
- RecruitingHealthy volunteers
Blood Flow Restriction Training on Upper Extremity Grip Strength
Casa Colina Hospital and Centers for Healthcare
- Location
- Pomona, CA
- Eligibility basics
- Ages 18–35