A group of medicinal cannabis users and supporters say the Ministry of Health was biased in its review of Government guidelines for accessing cannabis products.

Former Council of Trade Unions boss Helen Kelly, Nelson teenager Alex Renton's mother, Rose, and Wairarapa teenager Grace Yeats' mother, Tracy, are part of the group demanding an urgent independent inquiry.

After the guidelines for the application process were reviewed, Associate Minister of Health Peter Dunne last month announced only minor changes, based on the advice of medical experts.

Marijuana has long been touted for being virtually side-effect free. Now, according to one new study, long-term marijuana use may have one negative caveat: gum disease.

After analyzing about 1,000 cannabis users in New Zealand, researchers found that those who smoked pot for 20 or more years had few health problems — with the exception of gum disease.

Lead researcher Madeline Meier, an assistant professor of psychology at Arizona State University, said of the findings,

Other than being at an increased risk of gum disease, people who smoked marijuana for up to 20 years during adulthood were generally as healthy as people who didn't light up, according to a new study.

The same researchers had previously found that marijuana users were at higher risk of cognitive decline and descent into lower social and economic strata, but the new study suggests the same isn't true for physical health.

"The only measures that seemed to indicate any really serious health problem was periodontal disease," said senior author Terrie Moffitt, of Duke University in Durham, North Carolina.

Terminally ill Helen Kelly says the Government has made her a "criminal" after a review of medicinal cannabis guidelines ended with little change.

More than a year ago the former Council of Trade Unions boss was diagnosed with terminal lung cancer and after trying a variety of different medications she resorted to cannabis for pain relief.

Kelly continues to illegally source her own drugs after her bid for medicinal cannabis was withdrawn - the result of a "complicated" application process, which required information that was "impossible to access".

Labour will legislate for medicinal cannabis "pretty quickly" after taking office, leader Andrew Little has confirmed.

Little said cannabis products should be available to anyone suffering chronic pain or a terminal condition if their GP signed off on it.

Labour MP Damien O'Connor has drafted a bill for Parliament that would shift the onus of decision making on medicinal cannabis away from the minister to GPs and medical professionals.

Currently individual applications must first get ministerial approval for medicinal cannabis. The first Kiwi to do so was teenager Alex Renton who died shortly after approval was given.

A compromise is being offered up in the debate about legalising cannabis in New Zealand.

It would involve the creation of special recreational cannabis clubs where people could take the drug in a controlled environment, with profits going back to the government.

It is an idea proposed by Massey University drug researcher Dr Chris Wilkins, who says it would bring benefits on a number of levels.

"What the club do, is people would just join the club and that would allow them to purchase cannabis how they like," Dr Wilkins told TVNZ's Breakfast today.

"It would be in a controlled structure in terms of the club and the club could only purchase cannabis from the government so there would be some control over the supply."

Leading drug researcher Dr Chris Wilkins from Massey University’s SHORE and Whariki Research Centre is calling for the adoption of a not-for-profit club model for cannabis, allowing regulated cannabis products to be sold legally. His proposal foreshadows an annual international conference on drug policy being hosted by Massey next week.

Under the proposal, Cannabis Incorporated Societies (CIS) will be permitted to legally sell approved cannabis products to registered adult members, but will also be required to pursue cannabis health objectives such as disseminating information on the health risks of cannabis, information on local treatment and counselling services, preventing the sale and use of cannabis by minors and minimising cannabis related harm and dependency.

A leading Auckland drug researcher is calling for regulated cannabis products to be sold legally in New Zealand. 

Massey University's Dr Chris Wilkins would like to see the adoption of a not-for-profit club model for cannabis.

The proposal would see licensed companies permitted to sell Government-approved cannabis products to registered adult members.

Products would only be produced and sold by the Government, ensuring a high price to restrict demand and generating tax revenue to support treatment counselling, health services and enforcement.

"The government will be the only producer and the only seller, and that's a means to keep the price high and also collect tax," says Dr Wilkins.

New Zealanders need to have an informed debate about cannabis, distinguishing recreational use from the drug's potential medical application, psychiatrists say.

In the latest issue of the New Zealand Medical Journal, which includes studies on self-reported medicinal use of cannabis and the effect of law changes on synthetic cannabinoid use, an editorial argues for clear public debate.

Bill's been given five months to live. He doesn't want to become a criminal, but he says he's got no choice.

A Christchurch man dying of cancer fears he will have to become a criminal if he cannot legally access medicinal cannabis. 

The 63-year-old man, who only wanted to be known as Bill for fear of persecution, said he was convinced of the therapeutic benefits of cannabis for cancer sufferers.

"It makes you sleep better, it makes you eat better and when you reflect on your life, as a person in my position would do, coming up to death, you can see it clearer."

Bill was diagnosed with a rare form of colon cancer called mucinous adenocarcinoma in February 2014, undergoing surgery in October 2015 to remove his large intestine.