In Anthony Roberts' PCT (it's sticked in a thread in this section of the forum), it advises a stack of Nolvadex, Aromasin, and HCG.

Aromasin is an aromatase-inhibitor used, but I don't have access to Aromasin and i'm therefore I can't use it in said PCT stack. So I am wondering if Proviron is a viable substitute for Aromasin, as Proviron is an aromatase-inhibitor as well.