Up until this year tampons and pads absorbency rates have NEVER been tested with actual blood. They used water/ saline to test how much they absorb... Which I don't think I need to tell you that blood is thicker than water...
https://srh.bmj.com/content/early/2023/07/03/bmjsrh-2023-201895.full
Nearly 1 and a half CENTURIES and they never tested them with actual blood 🥲