Canadians suffering from terminal illnesses and chronic conditions such as arthritis can legally grow and smoke cannabis, or designate someone else to grow it for them, under regulations that take effect today.
The new rules are part of the first system in the world that includes a government-approved and paid-for supply of cannabis, now being grown in a former mine in northern Manitoba.
The rules will increase the number of people beyond the 292 in the country currently exempted from federal drug laws that make it a criminal offence to grow and use cannabis.
While some in Canada complain the new regulations create bureaucratic hurdles for doctors who may find themselves prescribing something they know little about, the Canadian system has been welcomed by medical cannabis advocates across the world.
"We're kind of envious of Canadians having the luxury of complaining about the minutiae of the programme," said Mr Chuck Thomas of the Washington-based Marijuana Policy Project. "It seems like a reasonable system."
Eight US states have taken steps toward permitting the medicinal use of cannabis. The US Supreme Court, however, ruled earlier this year that there is no exception in federal law for people to use cannabis, so even people with state medical exemptions could face arrest if they do.
In Canada, attitudes are different. Justice Minister Anne McLellan said the issue of decriminalising cannabis should be studied, and the Supreme Court of Canada has agreed to consider a challenge against the constitutionality of criminal cannabis laws.
The new health regulations were drawn up after a court ruling last year that gave the government until July 31st to create a way for people requiring cannabis for medicinal purposes to legally obtain it.
The new rules permit drug possession for the terminally ill with a prognosis of death within one year; those with symptoms associated with specific serious medical conditions; and those with other medical conditions who have statements from two doctors saying conventional treatments have not worked.
Eligible patients include those with severe arthritis, cancer, HIV/AIDS and multiple sclerosis.
More than 500 new applications are pending, and more are expected, according to the federal health ministry.
The Canadian Medical Association, which represents tens of thousands of doctors, opposes the new regulations because they make physicians responsible for prescribing a substance that lacks significant clinical research on its effects. Without the co-operation of doctors, patients cannot get medical cannabis exemptions.
Under the regulations, people can grow and possess cannabis for medical needs, or name someone to grow it for them, including the government.
In Flin Flon, Manitoba, a mining town hundreds of miles north of the US border, Prairie Plant Systems is growing cannabis in a former copper mine under a government contract.
Later this year, it expects the first harvest of cannabis that will be supplied by the government to eligible patients and used for research on therapeutic effects. Company head Mr Brent Zettl uses the same techniques that were used to grow berries and roses in the tapped-out mine beneath Trout Lake.
In town, a novelty store has sold 6,000 T-shirts bearing a new slogan for Flin Flon - Marijuana Growing Capital of Canada.