Your testosterone levels will gradually lower back down to baseline values roughly 2-3 weeks following cessation. Because of that, coming off HARD FX is incredibly easy. Continue to consume enough calories to support the new muscle mass you gained. If you do not, you will likely lose your gains because you are not giving your body the protein and calories it needs to sustain your new growth.
In addition, it is also very important that you continue to train heavy and hard when your break begins. Your body will only hold onto your new muscle and strength IF it has a need to. So if you slack in the gym and with your nutrition following use of HARD FX, don't be surprised to see your gains fade.
After taking four (4) weeks off from HARD FX, you make begin your next eight (8) week period of HARD FX.