Letro would be much more effective for reducing gyno, but you should know the side effects can be pretty drastic. Your sex drive will be gone for starters. I notice no side effects on Nolvadex. Long story short, letro crashes estrogen in the body, and Nolvadex works at the receptor where gyno is "created" to block estro from attaching. Both work, but letro is more effective. I would start with nolva, and if it doesn't shrink, go to letrozole.