Health Canada is spending $1.5 million to air recycled ads on prescription drugs and pot in the run-up to the fall federal election.

The federal health agency started re-airing the ads Monday that will run on TV and online until Aug. 8.

Health Minister Rona Ambrose says the ads illustrate the harmful effects of prescription drug abuse and the impact of marijuana use on the developing brains of teenagers.

"Our government will continue to raise awareness about the harmful effects of drug abuse and encourage youth to choose a drug-free lifestyle," Ambrose said in a statement.

The government will turn off the publicly funded advertising taps when the writ drops, expected after Labour Day as a result of October's fixed-election date.

The original installation of the taxpayer-funded marijuana ads ran alongside a radio ad campaign paid for by the Conservative party, which took aim at Liberal Leader Justin Trudeau over his promise to legalize and regulate marijuana.

The Canadian Medical Association, the College of Family Physicians of Canada and the Royal College of Physicians and Surgeons of Canada refused to endorse the campaign, saying it had become a "political football on Canada's marijuana policy."

"As the largest national organizations representing Canada's doctors, the CFPC, CMA and Royal College were invited to co-brand and provide expert advice on an upcoming public education campaign initiated and funded by Health Canada," said a joint-statement issued last summer.

"We did not, and do not, support or endorse any political messaging or political advertising on this issue."