It's not really something to add to a pct. It's for situational use, much like a PDE5 inhibitor.
Expect to feel a general malaise while it's active in your system (2-3 days). It, and many related compounds which activate melanocortin receptors are very functional, however.
I have not come across anything that can counteract or diminish their effects. Strangely, however, there seem to be some people who do not respond to it.
By no means a scientific hypothesis, but everything I've seen suggests an all-or-nothing efficacy.