A Tasmanian mother has told a parliamentary inquiry how medicinal cannabis has miraculously improved the health of her nine-year-old daughter who suffers from a rare genetic disorder.

Nicole Cowles was the first person to address the Tasmanian Upper House inquiry into legalised medicinal cannabis, which began public hearings today.

The inquiry, chaired by independent MP Ruth Forrest, was set up after Health Minister Michael Ferguson knocked back a proposal for a medicinal cannabis trial in Tasmania's Huon Valley in July.

Ms Cowles said she used the drug to control the severe seizures that had afflicted her daughter, Alice, from birth.

She said Alice took medicinal cannabis orally in liquid form every four hours and it was difficult to overstate the benefit her daughter received from the drug.

"Possibly the hardest thing in fighting for medical cannabis to be legalised is that I want to be able to tell people that this is a miracle. It's amazing," she said.

"But you can't use words like that when you're trying to put forward an argument for something that has real medical benefits because it sounds like you're selling snake oil, and that's not what we're doing.

"But for intents and purposes it really is a miracle, the difference in Alice's overall health and wellbeing."

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Ms Cowles said she has been overwhelmed by the response since going public about using medical cannabis to treat her daughter.

She said she has been contacted by scores of people in chronic pain or watching terminally ill loved ones suffer since telling her family's story.

"These are the real stories that come up over and over again," she said.

"So originally I spoke publicly because I thought it would help to protect Alice and I with what we were doing, but it's become bigger than that."

Ms Cowles also told the inquiry that Alice's respite carers were not able to administer the treatment because it was illegal.

Psychiatrist: cannabis is not necessarily 'safe'

Dr Eric Ratcliff, from the Royal Australian & New Zealand College of Psychiatrists, told the inquiry a medicinal cannabis trial "probably would be a good idea" but it must be a proper scientific trial and not one based on "a few stories that tug at the heartstrings".

Sorry, this video has expired Push to take medicinal cannabis use to federal level ( Ellen Coulter )

He said he and his colleagues wanted to inject some caution into the hearing because they knew the dangers cannabis posed in terms of psychosis and schizophrenia.

"There is a concern that your deliberations and the publicity surrounding them is assisting the idea that this is a safe, versatile drug without dangers and this is not the case," he said.

He said over the past 40 years illegal cannabis had been cultivated to contain higher and higher concentrations of tetrahydrocannabinol (THC) and that lawful crops should be far less potent.

"It's been modified in a way that's negative. What we've go to do is redress that, go back to a product that is more balanced and less likely to cause the adverse effects that we've observed," he said.

Council keen to adopt a new industry

The inquiry also heard from the Huon Valley Council which looked favourably upon medicinal cannabis as a potential new industry for the region.

Given the Huon Valley's high rate of youth unemployment the council was keen to adopt a promising new industry, believing medicinal cannabis would help diversify the local economy and improve economic development.

The Tasmanian Government had already made a written submission to the committee saying it would back clinical testing in the right circumstances.

The New South Wales Government, meantime, was setting up a clinical trial of medical marijuana.

On Wednesday Prime Minister Tony Abbott weighed into the debate saying he had no problem with the medical use of cannabis.

The revelation was was picked up by the Opposition's Lara Giddings in State Parliament.

"I never thought I'd see the day where I absolutely agree with Tony Abbott and the comments he's made around medical cannabis," she said.

Premier Will Hodgman wants to discuss consistency and security around medicinal cannabis at a federal level.

The issue is expected to be on the agenda at next month's Council of Australian Government's (COAG) meeting in Canberra.

The Upper House inquiry will hold more hearings on Friday and Monday.