I would run IGF-1 with an androgen. IGF-1 is the most anabolic substance known to man (aside from insulin), so stacking an androgen would be beneficial. As far as why many people use it in PCT, it's because it's a peptide hormone that will preserve LBM, allow you to drop fat mass while eating more carbs than maintenance, and has no suppressive effect on your HPTA. Basically it allows you to be on something anabolic even during your recovery period from AAS. Personally I use it during PCT and on cycle. I alternate one month IGF-1, one month slin. Definitely not recommending that to a novice, but it's what I do.