Weight loss · California
Weight loss and obesity studies in California
96 studies have at least one recruiting site in California. Weight-management research includes trials of new medicines, devices, diets and lifestyle programs for people with overweight or obesity, and studies of weight-related conditions such as fatty liver disease.
96 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
3 studies with pay posted
Exact amounts posted by the research company for each study. The button opens that study’s own page.
Pays up to
$32,150
Clinical Trial Opportunity for Healthy Adults with Overweight or Obesity (N-38160)
Altasciences · Cypress, CA
Schedule options pay $17,750 or $32,150.
Male/Female
View study & apply (opens in a new tab)Opens Altasciences’s page for this exact study
Pays up to
$25,000
Research Study for Obesity (N-34300)
Altasciences · Cypress, CA
Male/Female
View study & apply (opens in a new tab)Opens Altasciences’s page for this exact study
Pays up to
$6,400
Overweight / Obesity
CenExel · Anaheim, CA
Ages 18–65 · Male/Female
View study & apply (opens in a new tab)Opens CenExel’s page for this exact study
More recruiting studies (pay not posted)
- RecruitingHealthy volunteersPhase 1Overnight stay mentioned
A Study to Investigate the Relative Bioavailability and Safety of Different Oral Formulations of Elecoglipron in Healthy Participants
AstraZeneca
- Location
- Glendale, CA + 1 other US site
- Eligibility basics
- Ages 18–55
- RecruitingHealthy volunteersPhase 1
A Study to Investigate Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of AZD1043 in Healthy Adult Participants Living With Overweight and/or Obesity.
AstraZeneca
- Location
- Glendale, CA + 1 other US site
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1
A Study to Evaluate Safety, Tolerability and Pharmacokinetics of Orally Administered TIX100 in Healthy Subjects
TIXiMED, Inc.
- Location
- Chula Vista, CA
- Eligibility basics
- Ages 18–70
- RecruitingHealthy volunteersPhase 1
Safety and Drug Concentrations of REGN20934 in Adults With Overweight or Obesity
Regeneron Pharmaceuticals
- Location
- Glendale, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1/Phase 2
First-in-human Study of the Safety, Tolerability, Pharmacokinetics, and Food Effect of ACCG-2671
Aconcagua Bio, Inc. a wholly owned subsidiary of Structure Therapeutics
- Location
- Lake Forest, CA + 2 other US sites
- Eligibility basics
- Ages 25–75
- RecruitingHealthy volunteersPhase 1
A Research Study on How UBT251 Affects Levels of Midazolam, Caffeine and Warfarin in the Blood of Participants With Excess Body Weight
Novo Nordisk A/S
- Location
- Cypress, CA
- Eligibility basics
- Ages 18–65
- RecruitingHealthy volunteersPhase 1/Phase 2
A Study of MET233 in Combination With MET097 in Individuals With Obesity or Overweight With or Without Diabetes
Pfizer
- Location
- Cypress, CA
- Eligibility basics
- Ages 18–75
- RecruitingHealthy volunteersPhase 3
A Study of Aleniglipron in Adults With Obesity or Overweight and Type 2 Diabetes Mellitus (ACCOMPLISH-2)
Gasherbrum Bio, Inc., a wholly owned subsidiary of Structure Therapeutics
- Location
- Fountain Valley, CA + 55 other US sites
- Eligibility basics
- Ages 18–79
- 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
- RecruitingPhase 3
Efficacy, Safety and Tolerability of Switching From Glucagon-like Peptide-1 Receptor Agonists (GLP-1RA) to Maridebart Cafraglutide in Adults With Obesity or Overweight (MARITIME-SWITCH)
Amgen
- Location
- Chula Vista, CA + 51 other US sites
- Eligibility basics
- Ages 18–99
- RecruitingPhase 2
Safety and Efficacy of ABBV-295 in Adults With Obesity or Overweight With Weight-Related Comorbidities
AbbVie
- Location
- Concord, CA + 58 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingPhase 1
Evaluation of the Tolerability of Cagrilintide in Participants Not Tolerating GLP-1-RA Therapies Due to Gastrointestinal Adverse Events
Novo Nordisk A/S
- Location
- Walnut Creek, CA + 9 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1
A Research Study Investigating How Adults With Overweight or Obesity, With or Without Type 2 Diabetes, Tolerate Switching to a New Treatment (Zenagamtide) From Their Current Semaglutide Medication
Novo Nordisk A/S
- Location
- Glendale, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingPhase 1
A Research Study Investigating How Adults With Overweight or Obesity, With or Without Type 2 Diabetes, Tolerate Switching to a New Treatment (Zenagamtide) From Their Current Tirzepatide Medication
Novo Nordisk A/S
- Location
- Glendale, CA + 1 other US site
- Eligibility basics
- Ages 18+
- RecruitingPhase 2
Study to Assess the Effect and Safety of ALV-100 on Maintenance of Weight Loss
Alveus Therapeutics, Inc.
- Location
- Oceanside, CA + 19 other US sites
- Eligibility basics
- Ages 18–75
- Recruiting
Randomized Study on Transoral Outlet Reduction and Lifestyle Changes for Weight Regain After Gastric Bypass
Boston Scientific Corporation
- Location
- Irvine, CA + 8 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 3
A Clinical Study to Evaluate the Effects of Enicepatide (RO7795068) in Participants With Obesity or Overweight Without Type 2 Diabetes
Hoffmann-La Roche
- Location
- Irvine, CA + 43 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 3
A Clinical Study to Evaluate the Effects of Enicepatide (RO7795068) in Participants With Obesity or Overweight and Type 2 Diabetes
Hoffmann-La Roche
- Location
- Irvine, CA + 44 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 3
A Study to Learn About the Study Medicine Called Berobenatide (PF-08653944) in People With Overweight or Obesity
Pfizer
- Location
- Canoga Park, CA + 29 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 3
A Master Protocol to Investigate Efficacy and Safety of Elecoglipron in Participants With Obesity or Overweight With or Without T2DM
AstraZeneca
- Location
- Lynwood, CA + 43 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 2
Study of Olatorepatide in Adult Participants Living With Overweight or Obesity Without Diabetes
Regeneron Pharmaceuticals
- Location
- Walnut Creek, CA + 20 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 3
Efficacy, Safety, and Pharmacokinetics of Tirzepatide (LY3298176) Once Weekly Versus Placebo in Pediatric Participants 6 to Less Than 12 Years of Age Who Have Obesity (ADVANCE-SURMOUNT-KIDS)
Eli Lilly and Company
- Location
- Oxnard, CA
- Eligibility basics
- Ages 6–11
- RecruitingPhase 3
A Study to Learn About the Monthly Dosing Study Medicine Called Berobenatide in Adults With Breathing Problems During Sleep and Overweight or Obesity Who Use a Breathing Machine (PAP) (VESPER-OSA 1)
Pfizer
- Location
- Riverside, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 2
A Study of LY3457263 Compared With Placebo in Participants With Type 2 Diabetes on a Stable Dose of Semaglutide or Tirzepatide
Eli Lilly and Company
- Location
- Santa Ana, CA + 24 other US sites
- Eligibility basics
- Ages 18–75
Who these studies look for
Most of these studies set a BMI range and may exclude people taking certain weight-loss medicines or who have had bariatric surgery. Some require a weight-related condition such as type 2 diabetes or high blood pressure.
Matching a page like this one never means you qualify. Each research team decides eligibility at screening.
Questions
Can I join a weight loss study if I already take a GLP-1 medicine?
It depends on the study. Many exclude people currently or recently on weight-loss medicines; others are designed specifically for them. The listing’s eligibility criteria and the study team are the only reliable answer.