The sticky is at the top of the steroids forum and called "taking steroids 101" even after doing alot of research i finally read it a couple years ago and i should of read it long before that, alot of good info in there. I coppied and pasted just a small portion of it.
Letrozole is the only pharmacological “cure” for gyno that I know of to have ever worked in bodybuilders. In a study conducted on rodents, Letrozole was able to effectively destroy breast tissue tumors (6), and it’s also been effective on many bodybuilders who have used it to eliminate an existing case of gynocomastia. In my case, I used letro to get rid of my own gyno, by starting with a dose of 2.5mgs/day and then lowering it by .25mcgs per week once my symptoms abated.
With regards to using this stuff on a cycle, unless you are extremely gyno prone, or need to reduce estrogen levels to virtually nothing (for a bodybuilding contest or whatever), it’s going to be too powerful for most people. Male and female competitors typically use it to get the last bits of estrogen related water retention out of them during the final weeks of contest preparation. But when used on a typical cycle, letro is generally overkill unless a ripped look with zero water and estrogen is desired or if the user is prone to gyno.