Actually i agree with Lion.
POSH u re misleading u should read the profile of letrozole, you would learn things.
Nolva old science
Letro third generation of AI behind Exemestane, Letro may shrinks bitch tits and gyno.
"How good is this compared with Aromasin and Arimidex, it’s too other main rivals? Well, In non-cellular systems, letrozole is 2-5 times more potent than anastrozole and exemestane in its inhibition of the aromatase enzyme and activity, and in cellular systems it is 10-20x more potent! It also lasts quite a long time in your body,but takes awhile to get going… Letrozole has a whopping 2-4 day (!) ½ life"
http://forums.steroid.com/showthread.php?t=199826