If you have anything more than a small amount of anabolic enhanced muscle, getting off the juice completely will cause a loss of gains. How much depends on the person and how they are still training and eating. However it will happen and it is always quite noticeable. Don't BS yourself and think there is some magic way to keep it all. All the HCG in the world won't do that. I am sure most getbiggers are aware of this fact.