The Tasmanian Opposition has called on the Government to do more to ensure medicinal cannabis becomes available for patients.

About 50 people gathered at a Hobart rally calling for the legalisation of the drug.

Many of those attending had personal stories to tell about how the drug had helped them deal with the side effects of cancer treatment, the impact of seizures as well as chronic pain.

Natalie Daley, who was diagnosed with a rare cancer two years ago, said taking cannabis oil had significantly improved her health.

"Within an hour of taking cannabis oil my nausea started to lift and within a week I was up off the couch," she said.

"I was back to being myself, being a normal mother and housewife - it was amazing."

Shadow attorney-general Lara Giddings said the Tasmanian Government should be putting money on the table for trials of the drug, like other states.

"I have tried to ask Premier Mike Baird from NSW to accept (a Tasmanian) as part of that trial, for instance, but he cannot and will not guarantee children from outside of NSW being part of his trial," she said.

Ms Giddings welcomed State Government moves to legalise one element of medicinal cannabis oil - cannabidiol, or CBD - but she said the other element, THC, also needed to be part of any product.

"It is a very positive step to see that the State Government is moving towards putting the CBD component of medicinal cannabis onto the poisons list," she said.

"But it's not just the CBD that's required in medicinal cannabis ... you also need to have the THC element as well.

"This is what we need proper medical trials to tell us ... what are the combinations of THC and CBD that you need to have right to be able to treat nausea for patients undergoing cancer treatments, to be able to treat epilepsy, or indeed treat bad chronic pain that some people find this is useful for?"

In a statement, Health Minister Michael Ferguson said the Government was committed to a collaborative approach to clinical trials with other states and territories.

"Tasmania's chief pharmacist is an observer on the expert panel advising on the NSW trial," he said.

"This cooperative, evidence-based approach is consistent with the recommendations of the Legislative Council inquiry into this issue."