Medical cannabis in the UK: prescriptions, sources, products and high-risk use

Background and AimsThe UK legalised medical cannabis in 2018, yet little is known about people accessing cannabis legally via prescription or those using cannabis for medical purposes without a prescription. This study aimed to estimate: 1) the percentage of people who use cannabis medically with and without a prescription; 2) the sources used to obtain cannabis; 3) the products used; and 4) the associations between monthly or more frequent (MMF) product use and medical cannabis use status. DesignNational repeat cross-sectional surveys conducted in September-November 2023 and 2024. SettingUK. ParticipantsPeople aged 16-65 who used cannabis in the past 12 months (n=4,414). MeasurementsInferential statistics compared outcomes by medical cannabis use status. Multivariable regression analyses estimated associations between MMF product use and medical cannabis use status. FindingsOverall, 13.0% of people reported receiving a medical cannabis prescription, 36.4% reported medical use without a prescription, and 50.6% reported no medical use. Cannabis was sourced through diverse routes; only 10.7% of people with prescriptions obtained all their cannabis from a legal medical prescription. People with a medical prescription had a higher probability of reporting MMF use of oils or liquid drops (aRR=3.51; 95% CI: 2.73-4.52), oil or liquid capsules (aRR=2.63; 1.99-3.47), vape oils (aRR=2.40; 2.03-2.84), edibles (aRR=2.41; 2.01-2.90), cannabis drinks (aRR=3.39; 2.69-4.26), solid concentrates (aRR=3.10; 2.29-4.21), hash or kief (aRR=1.82; 1.44-2.30), and topicals (aRR=3.42; 2.58-4.51) than people who did not report medical use, after adjusting for covariates. People who ever asked for a medical prescription and people with a medical prescription in the past year had a higher probability of screening positive for high-risk use. ConclusionOver one in ten people who use cannabis in the UK report a medical cannabis prescription, yet a third reported medical use without a prescription. With only a minority obtaining all their cannabis legally, many rely on illegal sources, suggesting prescriptions may not meet the needs of those reporting use for medical purposes. People with prescriptions show a higher probability of frequent use of processed, higher-potency products, and meeting a threshold for high-risk use. Healthcare encounters during medical cannabis prescribing should discuss risks related to potency, product type, and adverse effects such as cannabis use disorder.