ive run 4 of these back to back to back... 2 on 1 off.. a little more aggressive.. i found my nuts started shrinking a bit during the 2nd cycle..its warranted.. im gonna continue to do them back to back as long as bloodwork checks out... just doing 4 weeks this time to give my body an extended break..then only 1 week of pct again... no sides..just a little oily skin..no hairloss and i am prone..roughly 7 lbs a cycle..cant beat that