Researchers at Western Sydney University surveyed women with endometriosis in New Zealand and Australia, where 72 per cent of respondents reported self-administering cannabis illicitly.
The women self-reported positive outcomes in using cannabis to manage the often painful condition, in which tissue similar to that which lines the uterus grows beyond it causing inflammation and scarring.
It is estimated that one in nine Australian women has endometriosis.
Just 23 per cent of the 186 Australian respondents accessed cannabis through a doctor's prescription, the study, published in the journal of Cannabis and Cannabinoid Research found.
Medicinal cannabis was approved for use in Australia in 2016.
The Therapeutic Goods Administration has said the majority of patients who seek medicinal cannabis do so for pain management but that the evidence for many painful conditions is still limited.
The administration does not consider medical cannabis a "first-line therapy" for any illness, meaning other treatments should be considered first.
Chief Scientific Officer with the Australian Natural Therapeutics Group and lead author Justin Sinclair said there was still stigma around medical cannabis and he was concerned people were using cannabis without medical supervision.
"A number of factors, including concern surrounding possible legal repercussions, judgement from either their doctor or society, or their doctors' presumed unwillingness to prescribe legal medicinal cannabis were the main reasons for not talking to their doctor," Mr Sinclair said.
"Improving doctor and patient communication about medicinal cannabis use may improve levels of medical oversight, the preference for legal medicinal cannabis adoption over acquisition via illicit supply and reducing cannabis-associated stigma."
Mr Sinclair said "on a positive note" almost all Australian respondents said they would continue to use cannabis as it provided better pain relief than current treatments.
