A woman's breasts don't stay the same size throughout her life, and hormones are a big reason why. Several factors influence how large the breasts grow, and certain life events shift that growth even further. Genetics help set a woman's natural cup size, but her hormones have an even more powerful effect. The key players are estrogen, progesterone, prolactin, and oxytocin.
Estrogen
Apart from certain medical conditions, the female body produces the most estrogen it ever will during puberty. It is no coincidence that this is also when a woman sees her fastest and most dramatic breast growth.
Pregnancy is another time of elevated estrogen. To prepare the body for breastfeeding, higher estrogen levels prompt certain tissues in the breast to grow and eventually fill with milk to nourish the child.
Each month during the ovulatory cycle, the ovaries trigger a smaller spike in estrogen. It is far less dramatic than during puberty or pregnancy, but still significant. The body does this to prepare for a possible pregnancy, and the higher circulating estrogen prompts the breasts to grow slightly. For women who notice swelling and tenderness around "that time of the month," this is the primary cause.
Progesterone
While estrogen works to increase the overall size and amount of breast tissue, progesterone acts on the cells responsible for growing milk ducts.
Progesterone and estrogen are closely linked during a woman's monthly cycle. Progesterone levels rise significantly in the first half of the cycle and eventually fall if pregnancy does not occur. Beyond supporting breast development, higher progesterone levels are associated with other benefits, including a happier mood, a lower risk of osteoporosis, and reduced susceptibility to certain types of cancer.
Prolactin
Prolactin is the main hormone that stimulates mammary tissue to produce milk. Interestingly, its production isn't limited to pregnancy; it also appears during the first few days of the menstrual cycle.
Like estrogen and progesterone, prolactin affects breast size. The effect is slight, causing the breasts to expand for a few days. During early pregnancy, estrogen and progesterone do most of the work of engorging the breasts; after the child is born, prolactin takes over and maintains the increased size by filling the mammary glands with milk.
Oxytocin
You may have heard oxytocin called "the feel-good hormone," largely because of its role in forming emotional bonds between people. Many consider it the chemical origin of what we call "emotional love."
Oxytocin also affects breast development by stimulating milk production. It works alongside prolactin and is secreted by the same part of the brain, the pituitary gland. Oxytocin is responsible for the deep emotional bonding that comes from breastfeeding.
Hormones for Natural Breast Enhancement?
If you're looking for ways to use these hormones to improve the size of your breasts, there are several breast enlargement herbs that are marketed to safely mimic the effects of these female hormones. We've reviewed and ranked the top products available today; have a look at our breast enhancement product reviews for more information.
