A 44-year-old cancer patient claims cannabis oil helped to reduce the size of a hole in his cheek caused by the disease.
The unnamed man was diagnosed with oral cancer in 2013 and underwent treatment to remove the deadly cells.
Despite initially working, the disease returned three years later and had even eroded a hole in his cheek.
But after using cannabis oil directly on his wound, it helped stop it from expanding and even shrank it by around 5 per cent, it is reported.
While each of his four daily doses also helped to give him around two hours of pain relief, according to a case report.
Published in the Journal of Pain and Symptom Management, it explains how the patient visited a palliative-care clinic in Toronto in 2016.
Diagnosed with oral cancer in 2013, he initially underwent surgery to remove part of the tumour.
Chemotherapy and radiotherapy was also used to help shrink the cancer - but it returned shortly after, LiveScience reports.
But after it had returned he had decided he would no longer seek further treatment to treat the disease.
Complaining of pain, he was given opiod-based medications. However, these proved to be unsuccessful.
Causing him to become drowsy, the main then asked Dr Vincent Maida, who helps to run the end-of-life unit at the University of Toronto for medical marijuana to alleviate his discomfort.
Using it in his vapourised form, he was forced to stop inhaling it when the disease created a hole in his cheek.
Seeking pain relief, the man then asked for a prescription to use medical cannabis oil.
Applying it directly to his wound, it was found to relieve his pain and helped to shrink the hole.
However, his condition deteriorated and he was admitted to hospital before passing away three weeks later.
Cannabis oil is made up of both cannabidiol (CBD) and tetrahydrocannabinol (THC) - the two main extracts from the plant.
Despite the latter often being overlooked in terms of its health benefits, the former is deemed a medicine in the UK.
In October, the regulatory body found CBD had a 'restoring, correcting or modifying' effect on physiological functions when administered to humans.
But the Class B drug itself was not recognised as having any benefits and is still illegal to possess.