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Making breastmilk

Your breasts make milk in response to your baby's suckling. The more your baby nurses, the more milk your breasts will make. Knowing how your breasts make milk can help you understand the breastfeeding process. The breast is made up of several parts, including:

Breast anatomy illustration

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How is breastmilk made?

Breasts often become fuller and tender during pregnancy. This is a sign that the alveoli are getting ready to work. Some women do not feel these changes in their breasts. Other women may sense these changes after their baby is born.

The alveoli make milk in response to the hormone prolactin (proh-LAK-tin). Prolactin rises when the baby suckles. Another hormone, oxytocin (oks-ee-TOH-suhn), also rises when the baby suckles. This causes small muscles in the breast to contract and move the milk through the milk ducts. This moving of the milk is called the "let-down reflex." Learn more about the let-down reflex.

The release of prolactin and oxytocin may make a mother feel a strong sense of needing to be with her baby.

How do I know if I will make enough breastmilk?

Many mothers worry about making enough milk to feed their babies. Some women worry that their small breast size will make it harder to feed their babies enough milk. But, women of all sizes can make plenty of milk for their baby. The more often your baby breastfeeds, the more milk your breasts will make.

Your baby's weight should double in the first few months. Because babies' tummies are small, they need many feedings to grow and be healthy. You can tell if your baby is getting enough milk by the number of wet diapers he has in a day and if he is gaining weight.

If you think you have or will have a low milk supply, talk to a lactation consultant. Visit the finding support and information section for other types of health professionals who can help you.

What will happen with your milk, your baby, and you in the first few weeks

Time Milk Baby You (Mom)
Birth Your body makes colostrum (a rich, thick, yellowish milk) in small amounts. It gives your baby early protection against diseases. Your baby will probably be awake in the first hour after birth. This is a good time to breastfeed your baby. You will be tired and excited.
First 12 to 24 hours Your baby will drink about 1 teaspoon of colostrum at each feeding. You may not see the colostrum, but it has what your baby needs and in the right amount. It is normal for the baby to sleep heavily. Labor and delivery are hard work! Some babies like to nuzzle and may be too sleepy to latch at first. Feedings may be short and disorganized. Take advantage of your baby's strong instinct to suck and feed upon waking every couple of hours. You will be tired. Be sure to rest.
Next 3 to 5 days Your mature (white) milk takes the place of colostrum. It is normal for mature milk to have a yellow or golden tint at first. Your baby will feed a lot, at least 8 to 12 times or more in 24 hours. Very young breastfed babies do not eat on a schedule. It is okay if your baby eats every 2 to 3 hours for several hours, then sleeps for 3 to 4 hours. Feedings may take about 15 to 20 minutes on each breast. The baby's sucking rhythm will be slow and long. The baby might make gulping sounds. Your breasts may feel full and leak. (You can use disposable or cloth pads in your bra to help with leaking.)
First 4 to 6 weeks White breastmilk continues. Your baby will now likely be better at breastfeeding and have a larger stomach to hold more milk. Feedings may take less time and may be farther apart. Your body gets used to breastfeeding. Your breasts may become softer and the leaking may slow down.

What if my breastmilk supply goes down?

If you don't feel as "full" as you did in the first few weeks of breastfeeding, you may worry that you are not making enough milk for your baby. Typically, after a few months of breastfeeding, a mother's body learns to make the right amount of milk for her baby. At this time, a mother's breasts may no longer feel "full."

Also, the baby may only nurse for short periods, such as five minutes at each feeding. These are not signs of lower milk supply. The mother's body adjusts to meet the needs of her baby, and the baby gets very good at getting milk from the breast. It's also normal for your baby to continue to nurse longer on each breast at each feeding.

What can affect how much breastmilk I make?

You may make more or less milk, depending on:

  • How completely milk is removed each time you breastfeed. An empty breast means better milk production.
  • How often you nurse or pump to remove milk. The more often you empty your breasts, the more milk your breasts will make.
  • The amount of milk your breasts store between feedings. If your breast stores too much milk between feedings (because your baby doesn't empty the breast), your breast will make less milk. If your breast is emptied, it will make more milk. It is common for one breast to make more milk than the other, and it is normal for babies to prefer one breast over the other. This can affect how much milk you make in that breast.

How can I make more breastmilk?

To increase your milk supply, you should always try to remove the milk completely from your breasts. You should do this quickly and often so that less milk builds up in your breasts between feedings.

To better empty your breasts, follow these tips:

  • Use breast massage and compression.
  • Offer your baby both breasts at each nursing.
  • Pump after nursing if your baby does not remove all the milk from your breasts. Your breasts will soften when the milk is removed. If the baby empties your breasts, then you can pump to remove milk and increase milk production between nursing sessions.

What is the let-down reflex during breastfeeding?

The let-down reflex (also called just "let-down" or the milk ejection reflex) happens when your baby begins to nurse. The nerves in your breast send signals that release the milk into your milk ducts. Let-down happens a few seconds to several minutes after you start breastfeeding your baby. It also can happen a few times during a feeding. You may feel a tingle in your breast or you may feel a little uncomfortable. You also may not feel anything.

Let-down can happen at other times, too, such as when you hear your baby cry or when you're just thinking about your baby. If your milk lets down as more of a gush and it bothers your baby, try expressing some milk by hand before you start breastfeeding.

Many factors affect let-down, including anxiety, pain, embarrassment, stress, cold, excessive caffeine use, smoking, alcohol, and some medicines. Mothers who have had breast surgery may have nerve damage that interferes with let-down.

All material contained on this page is free of copyright restrictions and may be copied, reproduced, or duplicated without permission of the Office on Women's Health in the Department of Health and Human Services. Citation of the source is appreciated.

Content last updated: July 21, 2014


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This information in Spanish (en español)


Breastfeeding fact sheet
(PDF, 160KB)

Your Guide to Breastfeeding
This easy-to-read publication has how-to information and support to help women breastfeed successfully.

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