Variation, yes, but you loose alot of what is injected, and some fo those mg are esters, but you are correct 100-150 mg a week will get a castrated man back to normal, hormonally at least. Now, a very athletic individual, or someone who just has a naturally high testoterone level will not benefit for long on 250 mg a week (although there certainly something to be said for the placebo effect... which I believe accounts for alot of claims of pro-hormone users... and yes the placebo effect can be VERY powerful and can contribute to noticable gains). Their htpa will be surpressed within a few weeks, and they will be back where they started. That is why I never recomend that low a dose, even for a beginer.