proviron will do quite the opposite...it will help your gains substantially as protein synthesis is increased and it will also serve to keep your member functioning properly.

i am running it during my current cycle and i definitely love it.

as far as nolva during cycle, it seems to be the general consensus from everyone who has done it that it helps keep water retention low and also prevents any gyno...you aren't losing any gains since it would have been water anyway.

so run it throughout if you have it to prevent any complications or just have it on hand to fight off any symptoms.