Doctors, medical researchers and cancer advocacy groups want the state government to legalise the use of medical marijuana, saying it is an effective treatment for pain including the side effects of chemotherapy.

In submissions to a NSW upper house inquiry into the issue, the Australian Medical Association, the Cancer Council NSW and the Australian Drug Foundation have all supported the use of medical marijuana in certain circumstances.

Relief: Tony Bower produces medical cannabis tincture. Credit: Melissa McDonald

The inquiry will conduct its first hearings this week.

Cancer Voices, a cancer patient advocacy group, is pushing for change. ''It is time for a sensible debate about this,'' Cancer Voices NSW chairwoman Sally Crossing said. ''This is not a political or religious issue; it is about being kind to people in a difficult situation, who are in a lot of pain and discomfort.''