Red blood cell capacity of modern menstrual products: considerations for assessing heavy menstrual bleeding.

This study found considerable variability in red blood cell volume capacity of menstrual products. This emphasises the importance of asking individuals about the type of menstrual products they use and how they use them. Further understanding of capacity of newer menstrual products can help clinicians better quantify menstrual blood loss, identify individuals who may benefit from additional evaluation, and monitor treatment.