Over time, the same dose will become less effective. Anyone who has stayed on cycle too long will sadly find this out for themselves, but as long as you keep your higher dosing for shorter periods, say 8-10 wks, and then lower to HRT dosing for 8-10 wks, you should be able to make gains for many cycles. The key is getting all of the other variables in order, diet, training and rest. Keep these things optimal, and eventually, when you stop seeing gain, you will know that it is time to either incresase the dose of your high periods or add a second compound