Testosterone feeds prostate cancer. Many of the drugs used to fight prostate cancer are designed to reduce testosterone, including Casodex, Zitiga, Lupron, etc.). And, often, as with myself, castration is a common step in the battle. Introducing more testosterone is throwing gasoline on a smoldering, or perhaps already ragging fire. I'm 73 and have learned to deal with virtually no testosterone, but it is infinity better than advancing my cancer artificially.