The test will prevent deca dick and the winny prevents the progesterone induced symptoms like bitch tits in lay mans terms.....U should be fine with the deca if you dont go over 400mgs and im of the belief to run deca for only 8 weeks as the progesterone sides dont rear there ugly head until week 7 for me(my nips get sensitive and a lil puffy) and i usually start my winny week 9 so that takes care of that for me.