It's actually the prolactin which it blocks. I like bromo but need to take 5mg/day(2.5 in am, 2.5 in pm) for 75mg/day of tren to combat it or my nips get leaky. I don't get the side effects others mention like headaches and loss of appetite, but I would start out with a lower dose of 1.25mg and work yourself up to see how your body feels.
I was considering it in the hope that I could use tren (the only thing thus far that has given me gyno symptoms), but too many have this same experience.