Don't think there would be any fake Genshi, it's a pretty new UGL so there would be no point in faking it. Deca will take 4-5 weeks to "kick in", though with any compound your blood levels will start to rise right after the first injection. Stacked with test you should at least have better pumps/more endurance etc. by week 2 IMO. Gains will start to pick up after that.