the half life of the drug in some cases is more important than the fact that it is 17 alpha alkyl, if taken too frequently before serum levels lower there could be cumulative toxicity, half life of this molecule is unknown at this point, kinetics and dynamics unknown, i am happy that one of our members found sucess with this product. its encouraging,,,were there any sides,,,especially hairloss? 1-AD scorched my scalp,,,can not afford to have that happen again