Menstrual products like tampons typically have an absorbency level listed on the side of their packaging. But until recently, that absorbency had never been measured with actual blood. Saline, a simpler and less viscous fluid, has been the default test liquid since absorbency standards were first set in the 1980s. However, researchers at Oregon Health and Science University recently tested the absorbency of products like menstrual cups, discs and period underwear, in addition to tampons and pads, with real blood in an effort to better diagnose heavy menstrual bleeding.

Bethany Samuelson Bannow is an associate professor of medicine at OHSU and a co-author of the study. She joins us to explain why research like this hasn’t been conducted before and what the findings could mean.