Breast milk usually begins to come in around 2 to 5 days after giving birth. Initially, the first milk produced after birth is called colostrum, which is rich in nutrients and antibodies and is produced within the first 24 hours. Then, between about the third and fifth day postpartum, the milk transitions from colostrum to what is often called transitional milk, which is creamier and produced in larger quantities. Around 10 to 14 days after birth, mature milk typically starts to come in, which is thinner in texture and contains varying fat content throughout a feeding. Several factors can influence the timing, including whether the birth was a cesarean section, stress levels, and health conditions such as diabetes. Breastfeeding frequently helps stimulate milk production and can influence how quickly milk comes in. In summary, most mothers notice their milk coming in within 2 to 5 days after birth, with full mature milk usually established by two weeks postpartum.
