I tried progesterone for about six months. Not long enough to have any physical effect, but I didn't like that it brought the "mental static" back, so I stopped. As it turned out, the girls filled out on their own after a few years, just on E. I think it was about 7 years after I started E that I started to notice the difference. It was enough that I keep reminding myself to go get them measured again one of these days, because my bras feel tight.