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Exploring The Effect Of Cannabidiol On Cannabis Tolerance Using A Novel Vaporiser Device In Heavy Users (Stage 1)
Sponsor: King's College London
Summary
Cannabis contains delta-9-tetrahydrocannabinol (THC), which causes intoxication. People who use cannabis frequently often develop tolerance, meaning they need to use more THC to feel the same effects. Cannabidiol (CBD) is another compound found in cannabis that is not intoxicating and may influence how THC affects the body and brain. This study will examine whether taking CBD changes how much THC heavy cannabis users consume to reach their usual level of intoxication. The study will also develop a new laboratory method that allows participants to safely and gradually self-administer THC using a vaporiser, similar to how cannabis is used in real-world settings. The study will include around 30 adults who use cannabis heavily. In the first stage, participants will take part in pilot sessions to help refine the THC administration procedure. In the second stage, participants will attend two study sessions and receive a single oral dose of CBD or placebo, in a random order. After this, they will inhale THC using a vaporiser and decide when to stop based on how intoxicated they feel. Researchers will measure how much THC is used, along with mood, mental health symptoms, thinking abilities, physical measures such as heart rate and blood pressure, and blood levels of THC and CBD. The results will help improve understanding of cannabis tolerance and whether CBD alters responses to THC in heavy cannabis users.
Official title: Exploring The Effect Of Cannabidiol On Cannabis Tolerance Using A Novel Vaporiser Device In Heavy Users: A Randomised Placebo-Controlled Experimental Study (Stage 1)
Key Details
Gender
All
Age Range
18 Years - 45 Years
Study Type
INTERVENTIONAL
Enrollment
10
Start Date
2026-03
Completion Date
2026-12
Last Updated
2026-03-13
Healthy Volunteers
No
Conditions
Interventions
delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD)
Vida T400:C20 Blueberry Cookies Medical Cannabis Cartridge (400mg delta-9-tetrahydrocannabinol and 20mg cannabidiol per cartridge)
Locations (1)
King's Clinical Research Facility
London, United Kingdom