University of California Needs Participants for Five Cannabis Clinical Trials

OG Article

Anthony Martinelli

06-13-2025

These studies, some of which have been ongoing since 2021 with others beginning more recently, all represent one of the most comprehensive university-led research efforts on marijuana’s medical applications currently underway in the United States. Each study focuses on a different therapeutic area, and all are currently open for eligible volunteers.

Trial of Cannabis Derivatives in Neuropathic Pain

Targeting veterans with high-impact chronic neuropathic pain (CNP), this four-arm randomized trial compares THC, CBD, a THC+CBD combination, and placebo. The goal is to determine the safety and efficacy of cannabinoids in reducing pain. The study is enrolling veterans who are not current cannabis users and who meet strict diagnostic criteria for neuropathic pain. Completion is expected by June 2027.

Brain Mechanisms Supporting Cannabis-Induced Pain Relief

Led by Dr. Fadel Zeidan, this pilot study examines how vaporized cannabis relieves acute pain by observing changes in cerebral blood flow using advanced fMRI techniques. Participants between 21 and 65 undergo controlled heat stimulation tests following cannabis administration via Volcano vaporizer. Participants receive either cannabis with 5.1% THC, or a placebo. Researchers collect both behavioral pain ratings and neurological data to assess cannabis’s direct effects on brain activity related to pain. The study runs through March 2027.

Cannabis Use, Cognition, and the Endocannabinoid System in HIV

Dr. Arpi Minassian is leading a randomized study to explore how low-level cannabis use affects cognitive performance and the endocannabinoid system in people with and without HIV. Participants, aged 18 to 65 and infrequent cannabis users, are randomized to receive THC, CBD, or placebo for five days. Researchers measure risk-taking, decision-making, and reward learning, along with biomarkers like homovanillic acid. The study will conclude by January 2026.

Effects of Cannabidiol and Tetrahydrocannabinol on Microbiome and Neuroinflammation in HIV

This randomized crossover study, led by Dr. Ronald Ellis, investigates how 14-day courses of oral THC and CBD affect inflammation, the gut microbiome, and the blood-brain barrier in people with and without HIV. Using fecal metagenomics and blood and CSF analysis, the study will determine whether cannabinoids reduce HIV-associated systemic and neuroinflammation. It runs through October 2027 and includes 100 total participants.

Effects and Mechanisms of a High CBD Cannabis Extract for CRPS

Also led by Dr. Fadel Zeidan, this study focuses on the impact of a high-CBD cannabis extract (BRC-002) on patients with complex regional pain syndrome (CRPS). Over a six-week treatment period, followed by two weeks of follow-up, researchers assess pain, inflammation, and psychological outcomes. Participants must have been cannabis-free for at least 30 days prior to enrollment. The trial will run through June 2029.