New federal restrictions on sugary alcoholic beverages took effect today, following at least two deaths in 18 months.

The alcohol content in what Health Canada describes as "single-serve flavoured purified alcoholic beverages" can no longer exceed 25.6 ml for each container of one litre or less.

The amount is the equivalent of about one and a half drinks; a single serving could previously contain up to four standard alcohol drinks.

The changes come after the 2018 death of Quebec teenager Athena Gervais, who drowned in a creek after quickly consuming several sugary alcoholic drinks.

Her death raised questions about the drinks and their marketing to youth and Health Canada consulted extensively on the matter before introducing the new rules today.

Given the "seriousness of the situation," Health Minister Ginette Petitpas Taylor said in a statement that the rules are effectively immediately and there will be no transition period.

Educ'alcool, a Quebec non-profit that promotes responsible drinking, say they are disappointed with the new rules, which they called too permissive.

The organization believes the federal government missed an opportunity to crack down on the relatively new industry.