The Ancient Sumerians Worshipped a Goddess with a 40-Day Menstrual Cycle - Apparently.
The ancient Sumerians, who lived in Mesopotamia (modern-day Iraq) around 4500 years ago, worshipped a goddess named Ninhursag, who was associated with fertility and menstruation. According to the Sumerian King List, a goddess with a 40-day menstrual cycle was said to have created humans, while a goddess with a 3-day cycle was associated with destruction and chaos. The Sumerians' knowledge of the menstrual cycle was surprisingly advanced for their time, and their mythological stories reveal a sophisticated understanding of female physiology.