I end my cycles at 8 weeks. myostatin for me is a bitch if i try to go longer its a waste of time and money if i try and go longer. i will how ever hit the prop hard in the final 2 weeks after the last injection of the 8 week cycle. and run it up to the final 3 days of teh enthanate ester. Thats what works for me, 10-12 weeks dont get me any where.