Breasts are made of a network of ducts, covered by a layer of fatty tissue. During pregnancy, estrogen and progesterone enlarge the milk ducts and multiply the glandular tissue that produces milk. After birth, these two hormones drop and allow prolactin and oxytocin to rise. Prolactin is the hormone responsible for milk production and oxytocin releases milk into the ducts. When you wean from breastfeeding, it may take several months for the prolactin levels to return to normal (which is why many of us can still hand express milk for a long time). However, once you stop breastfeeding, the milk making structures actually self-destruct – a process that involves massive cellular suicide, and the removal of the debris. Approximately six months after weaning, the milk-producing tissue is replaced with fatty tissue. If you return to your pre-pregnancy weight, your breasts most likely will return to the same size. They may not be as “perky” because the skin is a bit more stretched and the connective and fatty tissues in the breasts often shifts during pregnancy and breastfeeding. While our breasts may look smaller after weaning most of us can expect that our breasts will return to a similar size as they were pre-pregnancy. They’re not a little more lived in and well loved.