I would say you could run deca for a long time,say 12-15 weeks, and still be ok since it takes a while for deca to get in you system since it has a long lasting ester...
"Up to a point a man's life is shaped by environment, heredity, and the movements and changes in the world around him. Then there comes a time when it lies within his grasp to shape the clay of his life into the sort of thing he wishes to be. Only the weak blame parents, their race, their times, lack of good fortune, or the quirks of fate. Everyone has it within his power to say, 'This I am today; that I will be tomorrow.' The wish, however, must be implemented by deeds."