No not using, but there are plenty of places to get info and I know a lot of people who have in the past. Studied this a lot for exercise physiology, its very interesting how it all works.
Basic stuff: stay away from tren (trenbolone, shit will fuck you up and give you Hulk rage...I knew a guy whose heart enlarged and he almost died....they use this shit on cattle iirc and its 5x as powerful as straight test), stay away from orals as they generally fuck your liver up and you would have to take stuff to detox (some guys dont care and take orals like dbol anyway...permanent liver damage isnt good.). Test, I mean, doctors prescribe the shit for low T people, so as long as you had a legit way to get it and didnt overdo it you would probably see pretty massive gains. There are definite side effects like the hair loss, mood changes, some guys get their sex drive all kinds of fucked up and cant even get hard....need to seriously weigh your options out and cycle off it properly if you do decide to go that road.