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
Effects of P24 on Postprandial Aminoacidemia
Amplifye
- Location
- Davis, CA
- Eligibility basics
- Ages 45–75
- RecruitingHealthy volunteers
A Study to Test the AdaptDx Pro Agreement in Rod Intercept Time With the AdaptDx in Healthy Subjects With Normal Vision (FlashBack)
AdaptDx, Inc.
- Location
- San Diego, CA
- Eligibility basics
- Ages 22–49
- RecruitingHealthy volunteersPhase 3
Study to Learn About Safety, Tolerability, and Immune Response of a Catch-up Pneumococcal Vaccine in Children and Adolescents
Pfizer
- Location
- Fair Oaks, CA + 49 other US sites
- Eligibility basics
- Ages 1–17
- RecruitingHealthy volunteers
(CIRRUS-2023-1) CLINICAL CLIN Assessment of PathFinder 1.0 on the CIRRUS 6000 and the CIRRUS 5000
Carl Zeiss Meditec-Dublin CoCe
- Location
- Mountain View, CA + 4 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
A Prospective Controlled Study to Evaluate the Safety and Effectiveness of Thermage® FLX Radiofrequency Treatment
Bausch Health Americas, Inc.
- Location
- Sacramento, CA + 5 other US sites
- Eligibility basics
- Ages 30–60
- RecruitingHealthy volunteers
Women's Hormonal and Metabolic Wellbeing Study
Daily Nouri
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–45 · Women only
- RecruitingHealthy volunteers
Detecting Pulmonary Hypertension With the Eko CORE 500 Digital Stethoscope
Eko Devices, Inc.
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 2
A Phase 2 Safety, Tolerability, PK, and Efficacy Study of CS-1103 Following Fentanyl Challenge With Naloxone Blockade
Clear Scientific, Inc.
- Location
- Glendale, CA
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 2
Caring Recharge Project for Caregivers of Individuals With Alzheimer's Disease
Photozig, Inc.
- Location
- Campbell, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Radicle GI Health RAATM: A Study Assessing the Impact of Health and Wellness Products on Gastrointestinal-Related Quality of Life and Related Health Outcomes
Radicle Science
- Location
- Del Mar, CA
- Eligibility basics
- Ages 21–105
- RecruitingHealthy volunteers
Radicle GI HealthTM VNB: A Study Assessing the Impact of Health and Wellness Products on Constipation and Related Health Outcomes
Radicle Science
- Location
- Del Mar, CA
- Eligibility basics
- Ages 21–105
- RecruitingHealthy volunteers
Comparative Self-collection for Cervical Cancer Screening Pivotal Study
Mel Mont Medical
- Location
- Sherman Oaks, CA + 10 other US sites
- Eligibility basics
- Ages 25–65 · Women only
- RecruitingHealthy volunteers
Shield Post-Approval Study Protocol
Guardant Health, Inc.
- Location
- Anaheim, CA + 48 other US sites
- Eligibility basics
- Ages 45–81
- RecruitingHealthy volunteersPhase 4
A Study to Learn About a COVID-19 Vaccine in Healthy Adults 18 Through 64 Years of Age
BioNTech SE
- Location
- Walnut Creek, CA + 4 other US sites
- Eligibility basics
- Ages 18–64
- RecruitingHealthy volunteers
Intalight Reference Database Protocol for VG200D
Intalight, Inc
- Location
- San Diego, CA + 2 other US sites
- Eligibility basics
- Ages 22+
- RecruitingHealthy volunteers
Establishing Normative Urodynamics Parameters for the Glean Urodynamics System in Healthy Adults
Bright Uro
- Location
- Tustin, CA + 2 other US sites
- Eligibility basics
- Ages 18–45
- RecruitingHealthy volunteers
Motiva Implants® Post-Approval Study
Motiva USA LLC
- Location
- Beverly Hills, CA + 32 other US sites
- Eligibility basics
- Ages 22+ · Women only
- RecruitingHealthy volunteers
Multicenter Trial of Antibiotic Eluting Graft for Promoting New Bone Growth in/Near Infected Bone Cavities
Elute, Inc.
- Location
- Los Angeles, CA + 11 other US sites
- Eligibility basics
- Ages 22+
- RecruitingHealthy volunteers
Philips FAST SpO2 Technology With Masimo Sensors for SpO2 Monitoring in the Neonatal, Infant, and Pediatric Populations
Masimo Corporation
- Location
- Modesto, CA + 1 other US site
- Eligibility basics
- Ages 0 mo–21
- RecruitingHealthy volunteersPhase 3
A Study on the Immune Response and Safety of an Investigational Combined Measles, Mumps, Rubella and Varicella Vaccine, When Administered as Intramuscular Injection to Healthy Children 15 Months to 6 Years of Age
GlaxoSmithKline
- Location
- Walnut Creek, CA + 14 other US sites
- Eligibility basics
- Ages 1–6
- RecruitingHealthy volunteers
EXoPERT EMERALD Clinical Study
EXoPERT
- Location
- Long Beach, CA + 8 other US sites
- Eligibility basics
- Ages 45+
- RecruitingHealthy volunteers
A Study to Evaluate the Effects of a Prebiotic Soda on Glycemic Control in Adults
Olipop, PBC
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 30–70
- RecruitingHealthy volunteers
CREST: Samphire Guided Care Program on Wellbeing, Work Productivity, and Quality of Life
Samphire Group, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–65 · Women only
- RecruitingHealthy volunteers
AI-Enabled Direct-from-ECG Ejection Fraction (EF) Severity Assessment Using COR ECG Wearable Monitor
Peerbridge Health, Inc
- Location
- Orange, CA + 7 other US sites
- Eligibility basics
- Ages 18+