Australia's first medicinal cannabis trial will begin next year at a Newcastle hospital.

About 30 adults will participate in the first of three trials, which will test whether medicinal cannabis alleviates symptoms and pain for terminally ill patients and chronic sufferers.

Patients will begin the treatment at the Calvary Mater Newcastle Hospital early next year with initial results expected by the end of the year, the NSW government said.

"We do not want patients or carers having to play pharmacist," Premier Mike Baird said in a statement.

"That is why it is so important to explore the safest and most effective ways we can deliver compassionate care and improve the quality of life."

The trial will be staged in two parts and it will evaluate two types of cannabis products - vaporised leaf cannabis and a pharmaceutical product.