Estrogen, along with anti-androgen medicines that suppress the effects of testosterone, stimulate the growth of breast tissue resulting in feminization of the chest in transwomen. This is one of the more desirable and important effects of estrogen for transwomen. It parallels the hormonal influences that occur in cis-women during puberty.
Except, in this situation, there are limitations.
During puberty, breast growth in cis-females doesn’t necessarily have an overall upper limit for cup size. That is, your genetics may be programmed for an “A” or “B” cup or it may facilitate you becoming a “C”, “D”, “DD” or even larger.
This has not been found to be the case in transwomen.
In general, the maximum cup sizes that are obtained while on estrogen are an “A” or a “B”. This is true no matter how long one has been taking hormones – whether it is 6 months or even more than 10 years.
It has been also determined that there is no additional growth in breast size, related to the estrogen, after one and a half years. What you have at that point in time is all that you will get via the estrogen effect.
If you want your breasts to be larger, then top surgery will need to be pursued.
Several studies have shown that between 70 – 80% of transwomen with gender dysphoria are not satisfied with the limited hormonal effects on their breast growth and they seek to undergo a breast augmentation.
That is, for the vast majority of transwomen, the effects of estrogen in stimulating breast growth are inadequate for their needs and in addressing their gender dysphoria.
Fortunately, the results of a breast augmentation for them are profoundly positive and successfully address their gender dysphoria.
For more information on MTF breast augmentation, you can contact our office.