As discussed, Mastebolin possesses anti-estrogenic properties which results in the elimination of many of the unwanted side effects that AS users may experience, such as gynecomastia, water retention and dangerous increases in blood pressure. Although Mastebolin is a weak steroid and on paper it has low androgenic properties, it has already been mentioned that in practice the androgenic properties appear to be slightly higher than in theory, and secondly Mastebolin is a DHT derivative.
Briefly however, the side effects that may occur with use of Mastebolin include hair loss (if prone to male pattern baldness), aggression and acne. If a user does experience acne with other androgens such as testosterone, then it is a real possibility that they may experience it with the use of Mastebolin. I know of people who experience only a few spots with the use of testosterone however when using Mastebolin they experience many more spots. On the other hand, there are users who seem to experience less spots on Mastebolin than they do on Trenbolone.