I would not reccomend doing this. You'll get much better results by doing biweekly injections. Sustanon is made up of 4 esthers one of which is very fast acting. You will probably still make some gains doing it this way because of the longer acting esthers, but you won't be getting the full benefit because of the shorter acting esther. At the very least I would inject once a week but prefer biweekly.