im a noob so i'm only going by what's in "pounds and inches". i believe the shortest round of hcg you can do is 23 days (that includes your 2 days of loading). the longest is 40. after you finish your Drops you are supposed to maintain the 500 cal diet for an additional 72 hours. i read on this forum that the longer your phase 2 is (up to a maximum of 40 days) the easier it is to stabilize. hope this helps.