What prescription pills are there to get bigger breast?

Thank you for your question. In general, there may be other risks associated with hormone therapy to change breast size. A safer and more predictable approach would be to use fat grafting or breast implants. I would visit with a board certified plastic surgeon to discuss your options in more detail.

Unfortunately,
there are no medications, prescription or over-the-counter, that can reliably
increase breast size. The FDA (Food and
Drug Administration) closely monitors all medications, and have not approved
any drugs for this purpose. While
Estrogen (a female hormone) stimulates breast tissue, causing it to enlarge,
hormonal fluctuations can affect all areas of the body, not just the breast;
since many of these effects are negative, hormonal therapy is not used to
enlarge the breasts. Do not trust anyone
selling an oral aid to increase your breast size. Schedule a consultation appointment with an
experienced, Board Certified plastic surgeon to discuss all of your realistic options
for increasing the breast size. If cost
is a concern, most surgeons offer a variety of financing plans, as well.

The medicine you describe does not exist.  Breast augmentation is a safe and effective operation that can be easily reversed.