letrozole is also known as femara. letro is 10-30x more effective than arimidex in it's ability to pass thru the cell membrane of lipid (fat) cells and inhibit the activity of aromatize -- in other words, letro is far superior in lowering estrogen levels in fat cells. This has two benefits for bodybuilders:

(1) Estrogen 'attracts' water, so less water retention
(2) an average male bodybuilder is around 6-10% bodyfat

That's a lot of lipid cells with aromatase inside them, so a substantial percentage of aromatase is left untouched by arimidex, due to its poor ability to enter lipid cells. arimidex is approximately 80% effective at inhibiting aromatase.. letrozole is around 95-97%.

Come and get some!

http://research-ology.com/shop/prod...&products_id=42

LION

notes:
1. J Clin Endocrinol Metab 2000 Jul;85(7):2370-7
2. J Steroid Biochem Mol Biol 1997 Nov-Dec;63(4-6):261-7