Formestane is a " weak androgen and mild aromatase inhibitor". So basically it's mechanism of action will be the suppression of estrogen production. Unfortunately the window for this type of intervention is limited to the immediate onset and development of gyno. In other words, once the tissue is fully developed and stable, no amount of estrogen suppression will assist you.
It should be noted that estrogen suppression is not without significant side effects. Estrogen is responsible for brain health, joint lubrication, serotonin and dopamine product/absorption, bone density, and skin health.
Another consequence of estrogen suppression is estrogen rebound. When you artificially suppress estrogen your trick your body into creating more testosterone. Then you remove the suppression drug and your left with high testosterone converting to high levels of estrogen. Thus causing your gyno to flare up again and grow.
My advice is to save up for surgery if it bothers you that much. Gyno is essentially caused by hormonal imbalances, with is exactly what you will be creating by self medicating.
