Letrozole Is the most powerful drug that you can find to fight gynecomastia there’s nothing stronger. It was improved in 1997 under the brand name Femara it was used to fight breast cancer in postmenopausal woman. Its a Typ 2 Aromatase inhibitor it works by binding to the Aromatase Enzyme preventing oestrogen being released. Its a very aggressive way to fight oestrogen quickly during situations where other means have failed This is a very Power drug so you don’t want really use this for to long haven said that for what it does and how fast it does It its a godsend for most bodybuilders who need results fast. If this doesn’t work nothing will period.