Testosterone
"Have been taking Testim 1% gel for the past several months....on and off.  Makes me feel better overall.  I'm 52 and about two years back had noticed a decrease in sexual performance for which I had previously been prescribed Viagra.  Notified doctor of increasing depression symptoms and fatigue/joint pain.  He added a testosterone test to annual blood test and my testosterone level was barely over 100.  Viagra no longer required and I note overall decrease in depression, increase in energy levels.  Note warnings on secondary exposure to children and pregnant females.  Wash hands after application.  No adverse side effects or drug interactions have been noted."