The length of time it takes for breast milk to dry up after weaning a baby varies from woman to woman. For some women who have nursed regularly for a long period of time, this process takes weeks or even months. For other women who have nursed only sporadically, it takes only a few days.
Demand and Supply
Breast milk is created on the basis of demand and supply. The more frequently you nurse your baby, the more milk your body produces. This process works in reverse as well: The less frequently you nurse your baby, the less milk your body produces. If you stop nursing at a time when your body is used to producing copious amounts of milk on a routine basis, such as with a young baby who nurses eight to 12 times a day or a baby going through a growth spurt, it takes your body a longer period of time to decrease and ultimately stop producing milk. If you stop nursing at a time when your body isn't producing a lot of breast milk, such as with an older infant or toddler, your body adjusts more quickly. The ultimate time line depends on your body; there is no one-size-fits-all time line for letting your milk dry up.
Weaning is the process of slowly -- and safely -- decreasing your milk supply. This can happen naturally over time -- as when an older baby begins eating solid food and needs less breast milk -- or it can happen artificially, when the mother purposefully starts decreasing the amount of milk her body produces. This gradual process serves two functions. First, it gives your baby time to adjust to her new diet, whether it be the addition of formula or solid food to replace breast milk. Second, it helps the mother avoid painful conditions like mastitis, which results from plugged milk ducts.
Decreasing Your Milk Supply
A nursing mother has options to help speed up the depletion of her milk supply. A supportive bra, such as a sports bra, physically restricts the expansion of the breasts, limiting the amount of milk you produce. While warm water helps stimulate milk production, cold showers and ice help decrease it. The ingredients in sage tea also help dry up your milk, while placing cabbage leaves in your bra -- against your breasts -- has a similar effect.
Weaning and Postpartum Depression
A decrease in your milk supply also leads to a change in the amount of certain hormones in your body. Prolactin and oxytocin are two hormones released by the body while nursing that help you bond with your baby; estrogen levels remain low until the baby is weaned. Once your milk dries up, levels of prolactin and oxytocin plummet while estrogen levels surge. In some women, this leads to late-onset postpartum depression.
Where the Experts Stand
The American Academy of Pediatrics and the World Health Organization urge mothers to nurse their children exclusively for the first six months of life. This means not introducing solid foods until the child reaches at least 6 months of age. Additionally, breast milk or formula should remain the baby's main source of nutrition until 1 year of age.