What is your age?
I'll help you out a little, then you must research...
H-drol,Havoc,Epistane are all very good PH's...however they all,like all PH's, have some amount of possible side effects.
Check out the OTC PCT guide Thread and you can also check out RPN's(havoc), IBE(Epistane) and Competitive Edge Labs(H-drol) forums on this site. There reps are all very helpful.
Do your research and train hard and you will see good results.