A trial-period is usually 3 to 6 months. Be consistent in this trial-period. Gradually intense each workout through this period as well. After 6 months, If you see change, stay with it. If not, don't continue. I've did almost 6 months plus on this program, more than I did in previous years. I went from 7.75 non-bpel to now 8.6 nbpel and 8.8 bpel. My erect girth is almost 6 inches. You do the math...