The New South Wales Premier Mike Baird says he is excited about the prospects of Australia's first medical cannabis trial for terminally ill adults.

Mr Baird and Medical Research Minister Pru Goward were given a tour of the Calvary Mater hospital today, where the trial is taking place.

Ms Goward said treatment will begin early next year.

"The intention of this trial is to test whether or not medical cannabis can improve the quality of life of patients in their final stages," she said.

The trial involves using both vaporised leaf cannabis and a pharmaceutical and the first results are expected next year.

Mr Baird said the research will improve the quality of life for thousands of terminally ill patients.

"Why are these people who are in the fight of their lives, why are they undertaking pharmacy in their backyards?"

"Why don't we get the best minds in the country to see whether they can solve this and let those with terminal illnesses spend time with themselves and spend time with their family."

The study will look at how cannabis can potentially alleviate symptoms in terminally ill patients including fatigue, loss of appetite and insomnia.

Newcastle University's Professor Jennifer Martin said the trial is all about finding a balance.

"To find out what sort of dose gives people benefit if it exists and what dose actually gives side effects such as psychosis or feeling unwell," she said.

"It will involve increasing doses of drug and measuring levels in the blood and linking those levels to patient benefits or side effects."

It is expected once the initial results are known the second stage of the trial will be rolled out to patients across metropolitan and regional hospitals.