Depends. For some people clomid and nolva will destroy libido and mood. I am prone to libido loss big time on nolva and I just never "feel" like I'm recovering because of this, albeit I am. I just like to feel like I am too though lol, so I use HGCenerate day 1 with my SERM. If you are not prone to any SERM sides you could start in week 3.