Researchers found that terpenes found in cannabis were as effective as morphine at reducing chronic neuropathic pain.
Medical cannabis was rated as more positive in terms of emotional and holistic effects.
Researchers say the treatment also has significantly fewer side-effects than conventional medicines.
A new study will be presented at the annual meeting of the British Pain Society in Glasgow.
Opioid use decreased following cannabis therapy and this decline grew more significantly over time.
More than half of those surveyed said it helped them to reduce their use of other pain medications.
UK patients reported improvements in overall quality of life, pain severity and symptoms of anxiety.
The findings have led to calls for more research into the effects of cannabis on surgical outcomes.
The studies have been selected for presentation at the IACM Conference on Cannabinoids in Medicine, Basel 2022.
Cannabis was safe, well-tolerated, and associated with meaningful reductions in pain.
