The size of a woman’s breasts can vary from person to person and they can also change throughout a woman’s life. If you lose weight, your breasts may become smaller and if you gain weight, your breasts may become larger. A woman’s breasts may also become larger during pregnancy and while breast feeding, then again around menopause (when a woman’s period stops completely).
There is no injection that you can safely use to increase your breast size. Although some women have plastic surgery to increase their breast size, there are many risks that should be carefully considered before going that route.