How can you increase the size of your mammary gland in your breasts?

Pregnancy: Seriously, pregnancy naturally increases the size of your mammary glands inside the breast.

Hormone responsive: The actual mammary tissue is hormonally responsive but the degree of response varies from one individual to another. While natural or endogenous alterations in hormone that occur with pregnancy, oral contraceptives, weight gain, thelarche/menopause may stimulate this growth, the potential stimulation of breast cancer raise concerns about prescribing hormones.

No natural augment: I suspect you are asking about ways to increase breast size without surgery. I've never seen any scientific literature or patient studies that show any real improvement without surgery. I thnk a consultation with a board certified plastic surgeon is the right place to start if you are thinking about breast enhancement.

You really can't.: Pregnancy or hormone use can stimulate glandular growth. But long-term hormone use is a risk factor for breast cancer. Fat grafting and breast augmentation with implants remain the best methods for increasing the breast size.