Anyone in Quebec looking to purchase or possess cannabis legally will have to be over the age of 21 beginning Wednesday, Jan. 1.

The province’s decision to up the legal age from 18 will mark the toughest age restrictions in Canada since cannabis was legalized 14 months ago. 

Regulators cited the impact of the drug on young minds when introducing the legislation, however, experts warn the decision may have unintended consequences. 

“The problem is the amount of cannabis that’s already present in the illegal market. We have to think long and hard about our ability to effectively enforce prohibition,” explained Daniel Weinstock, director of the institute for health and social policy at McGill University.

“And if we can’t — and I strongly suspect we won’t be able to — … we risk finding ourselves in the worst of all possible situations.”

According to Weinstock, worst-case scenario would see 18 to 21-year-olds turning to the unregulated black market to purchase their cannabis.

However, given the legal age for drinking alcohol and smoking tobacco in Quebec remain at 18, there could be constitutional challenges.

“I think it’s absurd and I think it’s contrary to the charter, I think it’s discrimination as to age,” said Julius Grey, a constitutional lawyer in Quebec.  

“It seems to me that it’s perfectly absurd to say that alcohol — which kills many more people than cannabis — is safe at 18, but cannabis is only at 21.”

Quebec has become home to the toughest cannabis laws in Canada, where the province has also prohibited smoking cannabis in public and home cultivation.