Plastic pervades modern life, and menstruation is no exception. Since the middle of the 20^th century, many tampons and menstrual pads have contained somewhere between a little and a lot of plastic in their basic design—sometimes for reasons that “improve” the design, but often for reasons less crucial.

Getting a handle on how much plastic waste comes from menstrual products is tough, in part because it’s labeled as medical waste and does not need to be tracked, and in part because so little research has even looked at the scope of the problem. But rough estimates for the likely output are staggering: In 2018 alone, people in the U.S. bought 5.8 billion tampons, and over the course of a lifetime, a