well 40mg is the starting dose nowadays for men. 100mgs is if you have run orals alot or you are just a fiend of strength gains. i'll tell you though you have to drink a shit load of water when on 100mg. i had to lower the dose because of it. its mild but not much more mild than winny just no joint pain. so thats a bonus. but it dries you out so i think you need extra water. you will add lean mass but nothing insane. you keep all of it though. it really hardens you and shreds you if you are lean and have the genetics or diet to look so. the strength is the main reason for doing the high dose. not the difference in mass. its the fact that you get tren like strength gains without the sides and its much easier to keep