I have been using Propecia for several years now. It has worked great in stopping my hair loss. Recently I was diagnosed with chronic fatigue syndrome (CFS). After eight months of suffering with CFS (lost my job, etc,) my doctor discovered that most of my hormones were at extrememly low levels. I am on hormone replacement therapy and am beginning to feel much better. Since Propecia is a hormone inhibitor I wonder if it may have caused my illness. I would like to hear from anyone else who has had a similar experience. I believe that Propecia and Proscar are similar drugs.