There is a limited conversion rate for any prohormone, so for the original 4 androstenediol was around 15%. For this new preprohormone it's less, but the truth is we just don't know. It converts to testosterone via a two enzyme pathway and also has to make it past the GI tract. You can't take more and more get more testosterone as the enzymes become saturated and can't convert anymore.
I don't remember what the recommended dose of 4DHEA (what you're calling 4ad) is of the top of my head, but go with whatever the mfg or most users recommend and you'll get test levels as high as possible with that dose.
