Tamoxifen - Nolvadex , Astralean not anabolic androgenic steroid , belongs to the group of sex hormones have been branded as an anti-estrogen . Antiestrogen blocks estrogen receptors and prevents the connection with the estrogen receptor . Thus, men used to prevent the formation gynecomastia , also prevents osteoporosis . In some cases, gives rise to memory defects , but not as strongly as for anastrozole . In its use is also a major risk " fatty " liver . The problem is that after the failure may be that accumulated estrogens in the body begin to occupy , it is appropriate to tamoxifen was combined with Proviron , which from the beginning prevents aromatization of steroids . As such, it can have a significant positive impact on HDL (good ) cholesterol . Tamoxifen can inhibit the effectiveness of steroids , says the majority, but a slight effect . Also promotes testosterone production in the testes . With this medicine may occur nausea , vomiting , flushing.