Long term chronic pain patients were able to reduce their opioid consumption after the introduction of funded medical cannabis, according to new research published in the Cureus Journal of Medical Science.
The five-month study, conducted at the Hospital of the University of Pennsylvania, followed 29 adults who had been living with chronic pain for a median of 11 years and were struggling to reduce their opioid medication despite other treatments.
The results showed a 65% reduction in mean daily opioid consumption – from 46.8 morphine milligram equivalents (MMEs) per day at baseline to 16.2 MMEs per day after one month, with the reduction sustained throughout the study period.
Seven patients – 24% of participants – were able to completely discontinue opioid therapy by the end of the study, with five achieving this by the second month. Pain levels also decreased significantly over time.
“Although cannabis has historically been characterised as a potential ‘gateway drug,’ it may also serve as a harm-reduction tool for some patients seeking to reduce reliance on higher-risk opioid medications,” the researchers said.
The study is unique as it focused on cost as a factor in medical cannabis access, an issue common in the UK. Participants had “consistently identified cost as a major barrier to initiating medical cannabis” before enrolling in the study, according to the researchers, who described their work as “the first prospective observational study evaluating medical cannabis as an alternative to opioids in a setting where cost was removed as a major barrier”.
Participants were recruited from a university-based outpatient chronic pain clinic and underwent monthly pain assessments using the Numeric Pain Rating Scale. The study measured daily opioid use in morphine milligram equivalents.
“There was a statistically significant reduction in mean pain scores that was sustained over the five-month study period,” the paper said. “These results suggest that medical cannabis may be a useful adjunct therapy for reducing opioid use, relieving chronic pain, and improving health-related quality of life.”
The authors were careful to note limitations, including the small sample size derived from a single clinical site and the absence of a control group. Because patients self-titrated medical cannabis products, there was variability in dosing and frequency of use, meaning the findings are not standardised.
However, they concluded that “when used under appropriate medical supervision, medical cannabis may represent an effective adjunctive strategy for reducing opioid use among patients receiving long-term opioid therapy”.
A 2025 survey found that 84% of UK doctors would be willing to prescribe medical cannabis to manage chronic pain if it were part of the NHS toolkit. A parliamentary report published the same year found that treating chronic pain with cannabis could save the NHS £1,037 per patient per annum. “Given the number of people with chronic pain in the UK then the potential savings amounted to over £23.6 billion,” the report claimed.
