I'm wondering what makes breasts grow bigger?

Breast size is: Likely to ^ w puberty, pregnancy, breast feeding ; possibly prior to your period. You can build up chest muscles w exercise ; weight lifting but it will not ^ the amt. Of fatty tissue. There are no pills, herbs or machines that will ^ breast size. Breast augmentation is surgical enlargement. A padded bra will ^ appearance of volume. A supportive, well fitting bra can also enhance appearance.