If you are talking about a NO2 product then you can use it year round. I take Ammunition and the only difference between my usage on and off season is I will take more the few months before the show to help maintain my muscle mass. In all the studies I have read there don't seem to be negative side-effects (granted many of these studies could be flawed...). Not sure about what exactly you are taking but if it s clean high quality supplement you should be ok.
