The break-in happened at around 2 a.m. PT at the Rexall Drug Store on Fraser Street near East 50th Avenue.
"When police arrived, they found the glass in the front door smashed and thieves had made off with one litre of methadone that is 10 times more potent than traditional medication," police said in a written statement.
On Feb. 1, B.C. pharmacists began dispensing the red-coloured Methadone, which is 10 times stronger than the orange-coloured solution that was previously used.
There is concern from authorities and health advocates that the switch to the more potent formula could result in overdoses, particularly by street users who obtain illicit methadone.
According to the College of Physicians and Surgeons of British Columbia, there were more than 14,500 people registered in the province's methadone maintenance program in 2013.