The latest birth control pill, Lybrel, promises to eliminate the menstrual cycle. In a one year study some 59% of the women taking it had no menstrual bleeding over the one year study period. (Noted is that some quit the study due to continued bleeding)
This is of course touted as safe, but is it really? We recently found out, after decades of use, that the "Pill" causes an increase in breast cancer. The connection is obvious as pregnancy causes an increase in undifferentiated cells in the breast that do not differentiate until shortly before giving birth. These cells are prone to cancer. I think there will be a breast cancer connection to this new pill as well.
But what else might arise?
Women's bodies are designed to lose blood on a monthly basis. In the process of losing this blood many nutrients are lost. Iron for sure but I am not sure what all is lost via the menstrual cycle. But what is observable is that when women hit menopause their instance of many diseases go up. These include heart disease, several cancers and IIRC mental illnesses as well. One of the theories behind this increase is that the loss of blood protects against these diseases by keeping certain nutrients from building up, possibly toxins also. I think in the next decade or two we will see these problems arise, hopefully it wont take the nearly 45 years to conduct studies like it took with the "Pill."