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 volunteersPhase 3
A Study on the Safety of an Investigational Chickenpox Vaccine, When Given to Healthy Children, 12 to 15 Months of Age
GlaxoSmithKline
- Location
- Huntington Park, CA + 14 other US sites
- Eligibility basics
- Ages 1–1
- RecruitingHealthy volunteersPhase 3
A Study on the Immune Response and Safety of an Investigational Chickenpox Vaccine When Given to Healthy Children 12 to 15 Months of Age
GlaxoSmithKline
- Location
- Canoga Park, CA + 46 other US sites
- Eligibility basics
- Ages 1–1
- RecruitingHealthy volunteersPhase 3
A Study on the Immune Response and Safety of an Investigational Chickenpox Vaccine and a Marketed Measles, Mumps and Rubella Vaccine When Administered as Intramuscular Injection to Healthy Children 12 to 15 Months of Age
GlaxoSmithKline
- Location
- Huntington Park, CA + 12 other US sites
- Eligibility basics
- Ages 1–1
- RecruitingHealthy volunteers
Non-invasive Liquid Biopsy Analysis of Epigenomics Signatures in Multiple Cancer Types
ClearNote Health
- Location
- San Diego, CA
- Eligibility basics
- Ages 21–80
- RecruitingHealthy volunteers
A Study Evaluating the Impact of Regular FODMAP-targeting Digestive Enzyme Blend Use on Gastrointestinal Symptoms in Individuals With Self-Reported Bloating
Kiwi Health Inc
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 2
A Study to Learn About mRNA Vaccines Against Influenza in Adults
Pfizer
- Location
- Walnut Creek, CA + 14 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Acellular Dermal Matrix Investigation in Breast Reconstruction
RTI Surgical
- Location
- Duarte, CA + 11 other US sites
- Eligibility basics
- Ages 22+ · Women only
- RecruitingHealthy volunteers
Generative AI Plan for Care Lab Study
Fitbit LLC
- Location
- Mountain View, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteersPhase 4
Comparing Sarecycline and Doxycycline Effects on the Skin and Gut Bacteria in Acne.
Integrative Skin Science and Research
- Location
- Sacramento, CA
- Eligibility basics
- Ages 9+
- RecruitingHealthy volunteers
Safety and Effectiveness Evaluation of the High-intensity Focused Ultrasound Device for Lifting Lax Submental and Neck Tissue
CLASSYS Inc.
- Location
- Los Angeles, CA + 4 other US sites
- Eligibility basics
- Ages 30–65
- RecruitingHealthy volunteersPhase 3
A Study to Evaluate Tradipitant on Treating Nausea and Vomiting Induced by GLP-1R Agonist Use
Vanda Pharmaceuticals
- Location
- Los Angeles, CA + 2 other US sites
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteers
Examining Olive Oil Extract on Knee Comfort and Function
Applied Food Sciences Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 40–75
- RecruitingHealthy volunteers
Effera Dose Response: Women's Health
Helaina Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–40 · Women only
- RecruitingHealthy volunteers
Decentralized Study to Evaluate a Dietary Supplement for Episodes of Mild Acute Stress in Healthy People
PLT Health Solutions
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18–60
- RecruitingHealthy volunteers
Immune Defense Protein Impact On Respiratory Immune Outcomes
Quantec Ltd
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 60+
- RecruitingHealthy volunteers
Autologous Hair Follicle Derived Secretome as Adjunct to Aesthetic Procedures
Acorn Biolabs Inc.
- Location
- Fresno, CA + 18 other US sites
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Data Gathering for A10900
Optos, PLC
- Location
- Anaheim, CA + 2 other US sites
- Eligibility basics
- Ages 22+
- RecruitingHealthy volunteers
Autologous Hair Follicle Secretome for Androgenic Alopecia (Single Site)
Acorn Biolabs Inc.
- Location
- West Hollywood, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteers
Evaluation of Gut-Related Well-Being and Mood Effects of a Daily Nutritional Food Ingredient From the Co-Fermentation of Fungal Mycelium (Pleurotus Pulmonarius) and Microalgae (Chlorella Vulgaris)
Koralo GmbH
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Evaluate the Continued Safety and Performance of the Foot and Ankle Products
Arthrex, Inc.
- Location
- Sacramento, CA + 2 other US sites
- Eligibility basics
- Ages 2+
- RecruitingHealthy volunteers
The Effects of a Nutritional Supplement on Sleep Quality
Athletic Greens International
- Location
- Santa Monica, CA
- Eligibility basics
- Ages 35–65
- RecruitingHealthy volunteers
cfDNA Assay Prospective Observational Validation for Early Cancer Detection and Minimal Residual Disease
Adela, Inc
- Location
- Duarte, CA + 15 other US sites
- Eligibility basics
- Ages 40+
- RecruitingHealthy volunteers
Accuracy Evaluation of the Owlet OSS 3.0-M1 Sensor in Toddlers and Preschoolers
Owlet Baby Care, Inc.
- Location
- San Francisco, CA
- Eligibility basics
- Ages 1–5
- RecruitingHealthy volunteers
Efficacy in Controlling Myopia in Young Children Using a Novel Spectacle Lens
SightGlass Vision, Inc.
- Location
- Oakland, CA + 13 other US sites
- Eligibility basics
- Ages 6–8