Pharmacies could soon be responsible for distributing medicinal cannabis that's grown in New Zealand.

Health Minister David Clark is introducing the Misuse of Drugs Amendment Bill to Parliament today, which he says will make cannabis products more easily available to patients with a terminal illness or in chronic pain.

An advisory committee will be established to review the current requirements for prescribing medicinal cannabis, and set minimum product quality standards to "improve patient safety and give medical practitioners confidence".

The scheme also allows for the domestic cultivation and manufacture of medicinal cannabis products, including oils and balms.

"There is increasing evidence to support the use of medicinal cannabis. Just last week, the World Health Organization noted that cannabidiol could have therapeutic value and did not carry any addiction risks," Doctor Clark said.

There will be statutory defence for terminally ill people to possess and use illicit cannabis, while cannabidiol will be removed from the schedule of controlled drugs.

Mr Clark expects the changes to take two years to become law so he's creating a legal defence for possession and use of illicit cannabis for people who are in their last year of life.

"This does not make it legal for the terminally ill to use cannabis, but it means that they will not be criminalised for doing so."