I've only been on phen for two weeks but the thought of possibly having a lighter cycles has me jumping for joy!!! My cycle is usually extremely heavy which is one reason I wanted to loose weight. My doctor told me that being overweight can cause my cycle to be heavier. It would be even better if I was the fortunate one not to have a cycle in 6 weeks WOOHOO!!!! But my advice to women who are still in their child bearing years (which is up to 50 these days) is to talk to your ob gyn about the effect phen is having on your cycle and ability to reproduce.