Clinical trials · California
Opioid Use Disorder clinical trials in California
We’re tracking 25 recruiting opioid use disorder studies with a site in California — including Phase 2, Phase 3 and Phase 4 studies, each written for real people, not researchers.
Recruiting studies in California
- NCT07631598Recruiting
Buprenorphine at Needle Exchange Programs to Prevent Overdoses
This study tests whether offering buprenorphine (a medication that reduces cravings and withdrawal) directly at syringe service programs (places where people get clean needles) can help people with opioid addiction stay safe and reduce overdose risk. If you use opioids and visit a syringe service program, this may be an option to explore.
Los Angeles, CaliforniaAges 18 years+ - NCT06655883RecruitingPhase 3
Testing suvorexant for insomnia in people with opioid use disorder
This study tests whether the sleep medication suvorexant (Belsomra) can help people with opioid use disorder who also have trouble sleeping. If you are stable on medication for opioid use disorder and have not used opioids in the last month, this trial may be an option for you.
Garden Grove, CaliforniaAges 18–70 - NCT07386769Recruiting
Brain activity during social interaction in opioid use
This study looks at how the brain works during social interactions in people who use opioids regularly. It may help researchers understand how opioid use affects the way you connect with others.
La Jolla, CaliforniaAges 18 years+ - NCT07420283RecruitingPhase 2
Study of Brenipatide for opioid use disorder
This trial tests a new medicine called Brenipatide for people with opioid use disorder who are already taking buprenorphine but still occasionally use non-prescribed opioids. It aims to see if the study drug can help reduce opioid use.
Fountain Valley, CaliforniaAges 18–75 - NCT07693270Recruiting
Study looking for markers of pain and opioid response after injury or surgery
This study is looking for biological markers (like blood tests) that can predict how people will respond to pain and opioids after a traumatic injury or surgery. The goal is to help doctors tailor pain treatment to each person.
La Jolla, CaliforniaAges 18 years+ - NCT04375033RecruitingPhase 4
Oral versus injection buprenorphine for opioid use disorder
This trial compares taking buprenorphine by mouth versus as an injection for opioid use disorder. It aims to see which option helps people stay on treatment and reduces opioid use over about a year.
Palo Alto, CaliforniaAges 18 years+ - NCT06323824RecruitingPhase 4
Methadone vs. buprenorphine for opioid use disorder treatment
This study compares two medications, methadone and buprenorphine, to see which helps people stay in treatment for opioid use disorder. You may be eligible if you are starting a new treatment episode.
Oakland, CaliforniaAges 18–99 - NCT06565416Recruiting
Pain & opioid treatment in Native communities
This study is testing better ways to treat pain and opioid use in Native American communities. It may help if you have chronic pain or struggle with opioids.
Arcata, CaliforniaAges 18 years+ - NCT06827288Recruiting
Helping emergency patients with opioid use disorder
This study tests different ways to help people who come to the emergency department with opioid use disorder. It aims to find which support strategies work best to connect them with ongoing care and reduce harm.
Colton, CaliforniaAges 18 years+ - NCT06872190Recruiting
CDS tool for opioid use disorder in the ED
This trial tests a clinical decision support tool for emergency department providers at UCSF. It helps doctors give better care that considers social needs alongside opioid use treatment. The study will ask providers and patients about how well this tool works.
San Francisco, CaliforniaAges 18 years+ - NCT07214467Recruiting
Adaptive brain stimulation for opioid use disorder
This study tests a new type of brain stimulation that adapts to your brain activity, aiming to reduce cravings and help you control opioid use. It is for people with long-standing opioid use disorder who have not gotten lasting relief from at least 3 treatment attempts, including medication.
San Francisco, CaliforniaAges 22–75 - NCT07226570Recruiting
Ibogaine brain mapping study for opioid use disorder
This study uses MRI and EEG scans to map how ibogaine affects the brain in people with opioid use disorder. You must already be scheduled to receive ibogaine treatment in Tijuana, Mexico, on your own, as the study does not cover treatment costs.
Irvine, CaliforniaAges 21–70 - NCT04356274Enrolling by invitation
Improving access to addiction and mental health care at VA clinics
This study tests an approach to help VA clinics reach more Veterans with proven treatments for addiction and mental health conditions. It focuses on clinic-level processes (not individual medications) to increase how widely evidence-based care is delivered.
Palo Alto, CaliforniaAges 18 years+ - NCT06399653Recruiting
Nerve stimulation for alcohol use disorder in veterans
This study tests a non-invasive device that gently stimulates a nerve in your neck (the vagus nerve) to see if it can help reduce alcohol cravings and improve daily functioning. It is designed for veterans who struggle with heavy drinking and want to explore a new treatment option.
San Diego, CaliforniaAges 21–65 - NCT06994338RecruitingPhase 2
Tirzepatide for alcohol use disorder
This study tests whether a medication called tirzepatide (a once-weekly injection) can help people reduce their alcohol consumption. It is for people who drink heavily, have a high BMI, and are actively seeking help to drink less.
Los Angeles, CaliforniaAges 21–65 - NCT06387290RecruitingPhase 3
Mindfulness and pain management for chronic pain on opioids
This study tests whether adding mindfulness training to standard pain management visits can help people with chronic pain who are taking long-term opioids. It aims to improve pain relief and reduce opioid-related risks.
La Jolla, CaliforniaAges 18 years+ - NCT06494904RecruitingPhase 3
Standard vs. High Dose Buprenorphine in the ER
This study compares a higher dose of buprenorphine (a medicine that helps stop opioid cravings and withdrawal) to the usual dose, given in the emergency department. It aims to see if the higher dose works better to start treatment for opioid use disorder.
Oakland, CaliforniaAges 18–65 - NCT06961058Recruiting
Telehealth vs. in-person follow-up for opioid addiction treatment
This study compares follow-up care after an emergency department visit for opioid addiction: either through telehealth (video visits) or in-person appointments. The goal is to see which method helps people stay in treatment after they leave the ED.
El Centro, CaliforniaAges 18 years+ - NCT07024498Recruiting
Buprenorphine follow-up after emergency care
This study helps coordinate ongoing care for people who start buprenorphine, a medication for opioid use disorder, while in the emergency department. It aims to connect you with continued treatment to support your recovery.
Irvine, CaliforniaAges 14 years+ - NCT06835582Enrolling by invitation
Checking Methadone and Its Breakdown Levels
This study is checking the levels of methadone and its breakdown products in your blood. It helps make sure the medication is working safely for conditions like opioid use disorder or chronic pain.
Lemon Grove, CaliforniaAges 18–70 - NCT07672015RecruitingPhase 4
Testing a new pain drug in surgery patients at risk for opioid dependence
This trial tests a new painkiller called suzetrigine for post-surgery pain. It's designed for people whose medical records suggest they may have a higher chance of needing strong painkillers (opioids) long after surgery. We want to see if suzetrigine works better at preventing that.
La Jolla, CaliforniaAges 18 years+ - NCT06218056RecruitingPhase 2
CBD for reducing cigarette smoking in a treatment center
This study tests whether a daily dose of cannabidiol (CBD) can help people who smoke at least 5 cigarettes a day cut down or quit. It is for people staying at a treatment center in Los Angeles where cannabis use is not allowed.
North Hollywood, CaliforniaAges 18–65 - NCT05607381Recruiting
Meditation program study for opioid-treated chronic low back pain
This trial studies how meditation may change brain activity and help people with long-lasting low back pain who are already taking prescription opioids. The goal is to understand the “neural” (brain) effects of meditation to improve pain treatment.
La Jolla, CaliforniaAges 18–65 - NCT06494891RecruitingPhase 2
Understanding motivation for IV alcohol drinking
This study looks at why people with alcohol use disorder choose to drink alcohol given through an IV. The goal is to better understand the motivation behind drinking, which could help improve treatments.
Los Angeles, CaliforniaAges 21–65
Opioid Use Disorder trials by city in California
Where these studies are running in California
Institutions with a site for the recruiting opioid use disorder studies listed above.
- University of California San Diego Health · 5 studies
- University of California, San Francisco · 4 studies
- Alameda Health System - Highland Hospital · 2 studies
- El Centro Regional Medical Center · 2 studies
- University of California, Davis Medical Center · 2 studies
- University of California, Irvine · 2 studies
- VA Palo Alto Health Care System · 2 studies
- Ark Clinical Research
What taking part in a opioid use disorder study involves
A screening visit first
Before anything else, the study team checks whether you fit — usually a visit with some tests. You can stop at any point, and screening is typically free.
Care at a nearby site
Study visits happen at a clinic or hospital taking part. Many studies cover the cost of the study treatment and related visits, and some reimburse travel.
You stay in control
Taking part is voluntary and you can leave a study at any time, for any reason, without affecting your regular care.
The team decides eligibility
Our fit check is a helpful first read, not a decision. The study team makes the final call after reviewing your health history.
Opioid Use Disorder trials in other states
Common questions
- Are there opioid use disorder clinical trials in California?
- Yes. We're currently tracking 25 recruiting opioid use disorder studies with a site in California, each rewritten in plain language so you can see what it's testing and who it's for.
- How do I find out if I qualify for a opioid use disorder study in California?
- Each study lists its eligibility rules — age, diagnosis, prior treatments. On every trial page we explain these in plain language and offer a short, optional pre-screen for a fit read. The study team makes the final decision.
- Do I have to live in California to take part?
- Not necessarily. These studies have a site in California, but eligibility is about your health, not your address — some people travel to take part, and a few studies reimburse travel. The study team can tell you what's required.
- Does it cost anything to join a opioid use disorder trial?
- Using Clin2 is always free. Many trials cover the study treatment and related visits; some reimburse travel. The study team explains exactly what's covered before you decide.
Not the right time?
New opioid use disorder studies open in California regularly. Set up a health profile and we’ll quietly watch for studies that fit you and email you when one opens.
Clin2 helps you find and understand clinical trials and does not provide medical advice. Study data comes from ClinicalTrials.gov. Talk with your doctor about whether a specific trial is right for you.