A large review suggests a lack of strong scientific evidence supporting the use of medical cannabis to treat conditions like chronic pain, anxiety and insomnia, according to University of California, Los Angeles (UCLA) Health.
More than a quarter (around 27%) of people in the US and Canada report having used cannabis to treat medical conditions. With so many turning to cannabis as a treatment, a team of researchers led by UCLA Health analysed more than 2,500 studies released between January 2010 and September 2025 to evaluate the efficacy of the drug in treating different conditions.
Their findings show clear benefits from cannabis use to treat a handful of conditions, including HIV-AIDS-related appetite loss, chemotherapy-induced nausea and vomiting and certain severe paediatric seizure disorders.
Evidence supporting the use of cannabis to treat other conditions, including chronic pain, insomnia and anxiety, remains unclear or insufficient.
[See more: Cannabis often exacerbates existing mental health struggles, studies find]
“While many people turn to cannabis seeking relief, our review highlights significant gaps between public perception and scientific evidence regarding its effectiveness for most medical conditions,” Dr Michael Hsu, first author and professor at UCLA Health, said in a press release. The majority of medical cannabis users, for example, report using it to manage chronic pain despite current medical guidelines advising against cannabis as a first-line treatment for such pain.
Using cannabis is also not without risks, particularly with higher potency products. Long-term data from adolescents suggested that high-potency cannabis may be associated with higher rates of psychotic symptoms and generalized anxiety disorder. Other studies linked daily use, especially of inhaled or higher potency products, with increased risk of coronary heart disease, heart and stroke as compared to non-daily use.
While the authors stress that while these findings indicate a need for careful risk analysis and screenings before recommending THC-containing products for medical use, they also caution that more research is needed. Several limitations to the review make further research “crucial to better understand the potential benefits and risks of medical cannabis,” explained Hsu. “By supporting more rigorous studies, we can provide clearer guidance and improve clinical care for patients.”
