I agree to bro, Deca should be run longer, but with a taper. 8-10 wks is when Deca would normally be getting really good, BUT this is because of the cummulative effect of the ester. If you are taking say 400mg.wk of deca, remember that around wk8 you are probably actually accumulating a dosage of almost 800mg in your system. Starting to taper down will stop this from growing, and even out your dosage, and cause you less problems. Its like you are catering to the ester. Remember that decanoate is one of the longest esters a bodybuilder can use.