Masteron de-sensitizes you to estrogen via blunting progestin receptors . progesterone is what makes you ultra sensitive to estrogen (which is why you can get tren or deca gyno even though they don't convert to estrogen, its that they activate progestin receptors) . SO if your progestin receptors are blunted, then your less likely to get estrogen side effects .
thats what MASTeron does .
its called MAST for a reason .. 'Mast" means 'breast' . it was invented to blunt progestin receptors and help female breast cancer.
the only steroid with the word "breast" in its brand name is obviously going to help with gyno to some degree , right
