Breastfeeding isn't in the cards for every woman. There are new moms who can't nurse at all, while others choose to use infant formula for their own personal reasons. Some moms breastfeed for limited amount of time and then decide to switch to formula. If you are lactating, you might wonder what happens to your milk if you choose to formula feed.
Because breast milk production is a supply and demand process, your breasts will eventually stop making milk, and the milk already in your breasts will dry up once you are no longer nursing, pumping, or hand expressing. The time it takes for your milk to dry up depends on if you breastfed at all, the amount of time you have been breastfeeding, and how much milk your breasts were producing when you switched your baby to infant formula.
According to the health website Very Well, while your placenta is in place, it is producing high levels of estrogen and progesterone that prevent the hormone prolactin from making a large amount of milk. Baby Center noted that these hormone levels decrease immediately after the delivery of your placenta, sending your body a message to start producing more breast milk.
For moms who don't breastfeed at all, their body begins to secrete prolactin inhibiting factor (PIF) which gradually shuts down milk production. As long as you aren't expressing any milk from your breasts, it should take about a week to 10 days for your body to stop producing milk.
However, if you have been breastfeeding for awhile and have a healthy supply of breast milk, it can take longer for your breasts to stop milk production. According to Belly Belly, the breast milk of moms who have nursed frequently over a long period of time can take weeks to many months to fully dry up.
Engorgement, or when your breasts are painfully overfull with milk, can happen if you're producing breast milk, but your baby is drinking infant formula. Baby Center recommended using a cold compress or ice pack on your breasts, and taking nonsteroidal anti-inflammatory medication such as ibuprofen to relieve the pain of engorgement. Don't bind your breasts, as this can cause mastitis and plugged ducts. You should also avoid stimulating your breasts, expressing milk, or facing the warm water in the shower to speed up the drying process.