1-AD and 4-AD?

Ive been hearing some things about this stuff but have absolutly no idea what it is. A guy at work told me people in his gym are adding a good 20 pounds of new muscle with this supposed miracle supp. Is it just another testosterone pre-cursor like mag-10 or testrogel and if it is why is it working better then the reports I get from those products like testrogel. Hit me back my comrades in arms!!!