All gains can and will be lost if you dont eat to maintain them! Every new lbs of muscle you add, you must eat to maintain it! Especially if you have surpassed your genetic potential. Also, if the cycle was short,its harder to keep gains! I always cycle for at least 12 weeks! I come off correctly and keep my food intake high, and lower my training so I dont go catabolic!
So, to be sure you understand, if you gain 10 lbs from primo and stop eating right, stop training or train too much and dont restore yoru HPTA, you will lose those 10lbs, even if its primo!