the longest i did was on trt, 20 weeks and its just idiotic to be honest... there's no reason to run cycles that long and i have not done it since... you get to a certain point, myostatin kicks in and you aren't gaining much of anything...
12 weeks and my recovery took a while cause i was using long esters. you not only have to count how many weeks you are injecting but you need to add the esters too.. in this example i was using deca and it will take a good 6-7 weeks to get out of your system. so essentially 12+7= 19 weeks on.. so you better give yourself 6 months to recover