This campaign is designed to tackle period poverty, which sees some many women across the world struggle to pay for sanitary products like tampons and pads.
The Period Products Bill puts a legal duty on the Scottish Government to ensure that such items are available free of charge for any women or girls who need them.
Ministers initially opposed the Bill, claiming a universal scheme could cost as much as £24m per year and arguing that the issue could be effectively tackled through local councils.
Free period products are already provided in schools, universities and colleges in Scotland, but the new law will make these initiatives permanent as well as extending the right to all women.
In England, all state schools and colleges have been able to apply for UK Government funding to provide free period products for students since January, through an “opt in” system.
Wales also introduced funding for free period products in schools from April last year, while one local authority in Northern Ireland offers them in public places