For most of recorded history, the monthly cycle was surrounded by silence, superstition, and — for many women — genuine hardship. Yet the story of how societies have understood, managed, and legislated around it spans 5,000 years of human history.

From softened papyrus in ancient Egypt to Kimberly-Clark's mass-market revolution in the 1920s, and from the mapping of the hormonal cycle to the countries now making hygiene products freely available by law — this is a history rarely taught in school.

The 15 questions below draw on documented health history, social science, and public health research. Some answers may surprise you.