Canada will be the first nation to start printing warnings directly onto individual cigarettes in a bid to deter young people from starting smoking and encourage others to quit.
The warnings, which will be in English and French, will include phrases like "Cigarettes cause cancer" and "Poison in every puff".
The new regulations go into effect on Tuesday.
Starting next year, Canadians will begin to see the new warning labels.
By July 2024 manufacturers will have to ensure the warnings are on all king-size cigarettes sold, and by April 2025 all regular-size cigarettes and little cigars with tipping paper and tubes must include the warnings.
The phrases will appear by the filter, including warnings about harming children, damaging organs and causing impotence and leukaemia.
In May, Health Canada said the new regulations "will make it virtually impossible to avoid health warnings" on tobacco products.
A second set of six phrases is expected to be printed on cigarettes in 2026.
The move is part of Canada's effort to reduce tobacco use to less than 5% by 2035 and follows a 75-day public consultation period that was launched last year.