There's an effective, environmentally friendly option for people with periods, and few know about it, research says

(CNN)They have been around since the 1930s, and still, many who menstruate are unaware of the alternative to pads and tampons: the menstrual cup.

They're safe and effective, and can save money and reduce waste and water usage, according to a study published Tuesday in the medical journal The Lancet Public Health, but they aren't well known among women.
"In any impoverished set of circumstances be it in Liverpool, or London, or anywhere in low-middle-income countries, people really struggle -- women and girls really struggle to be able to manage their menstruation," and menstrual cups can be a part of the solution, said Penelope Phillips-Howard, senior author of the study, which analyzed 43 international papers.
Menstrual cups "