breast milk made

How Is Breast Milk Made?

Recently I read a post saying, “I produce breast milk, what is your super power?”. I love this post because the making of breast milk is such an intricate and fascinating process. Breast milk is the gold standard when nutrition for your baby is concerned, but where does it all start? If we go back to the beginning, it is easy to see that it starts at the breast.

Breast milk production

 It All Starts With The Breast

During pregnancy you might have experienced that your breasts are changing as they are getting ready to breastfeed. Breast milk known as colostrum, is made by your breasts from your second trimester of pregnancy. Although you might not see it yet, it is there and will come into full flow when your placenta is birthed. Some mothers do however leak colostrum (refer to our article “what is colostrum?” to find out more check this article. So what changes happen to your breast during pregnancy?

  • Breast’s grow larger, skin appears thinner and veins more prominent
  • Nipples become more erect
  • Intensified areola (dark portion of the breast) pigmentation
  • Enlargement of Montgomery glands (bumps on your areola)
  • Ductal system of breasts becomes more specific for breastfeeding
  • Increased size of lobes, lobules and alveoli

breast milk production

Hormones that Help with Breast Milk

You have guessed it “hormones”. During pregnancy, it is a known fact that women are more emotional, Certain hormones increase during pregnancy to meet the needs of the growing infant (as well as mother). The main hormones involved with breast milk include: oestrogen, progesterone, prolactin and oxytocin.

Oestrogen and Progesterone

Oestrogen and progesterone are two well-known hormones that assist with the female reproductive system. Oestrogen is responsible for bringing about changes to the breast to get it structurally ready to breastfeed (1). Oestrogen does not work during pregnancy only, but also during puberty (cause breasts to grow and develop) and ovulation (Keeps breast from decreasing in size again). Although oestrogen helps the breasts to develop, it does not produce breast milk, but rather prevents it. Progesterone assists oestrogen with this. Progesterone is also responsible for increasing your lobules. During pregnancy, your placenta releases both oestrogen and progesterone, therefore when your placenta is “birthed”, your breast milk will gradually increase (1).


Prolactin is a prominent hormone during pregnancy and can reach concentrations often up to 10 to 20 times higher during pregnancy than at other times (1). Prolactin promotes breast milk production and comes into full action when placenta is removed. After birth, prolactin levels often decrease to blood concentrations present prior to pregnancy.  These levels do increase for up to 60 minutes each time the mother breastfeeds her infant and are often highest at night (remember to feed your baby at night) (1). A baby that suckles on her/his mothers breast causes more prolactin to be released and therefore more breast milk to be made. The more the mother removes breast milk from the breast, the more breast milk she would be able to make. Prolactin naturally becomes less at 6-9 months after giving birth.

Exclusive Breastfeeding My Baby


Oxytocin (aka the “love” hormone) is a hormone that stimulates the release of breast milk from the breast as it causes the cells of the breast to tighten when the baby sucks at the breast (1).  This process is known as the “let down reflex” (2). Breast milk can often not be apparent for up to 30 seconds as a section in the brain has to first pick up the sensory impulse of baby sucking at baby’s breast. A baby sucking at the one breast will cause breast milk to come down in the other breast as well (which is why you will see a mother often holding a tissue on the other breast even if the baby is not sucking on that one). You know oxytocin is being released if:

  • You feel a tightening in your breast
  • You feel thirsty
  • You are feeling your uterus contract (pains in your abdominal area)
  • Breast milk is squirting from your breast when your baby abruptly detaches

Factors that increase oxytocin include (2):

  • Skin-to-skin
  • Rooming in (mother is able to see, touch and respond to her infant aids in relaxation)
  • Relaxing

Although, these factors promote the release of oxytocin, stress can stop the release. Therefore, if a breastfeeding mother becomes stressed, her breast milk release can become less. The moral of the story: try to relax, make yourself a cup of tea, take that long bath.

love hormone

How do I Know if I Have Breast Milk?

A question that is asked frequently is: “How do I know I have breast milk? Well, the simple answer is to express and see, but sometimes if we express we might not see anything. Does this mean you have no breast milk…not necessarily! Glance quickly back at the previous section, it takes about 30 seconds for the breast milk to come down first of all. Second a lot of mothers are under the impression that colostrum is not breast milk (which is false). Thirdly even though your breasts feel empty, they are not. Day 1 to Day 3 after birth, your breasts may not feel full yet, it is at this stage where you are producing colostrum. Colostrum comes out in 1-3 teaspoons at a time and is enough for your baby. From Day 3-5 breast milk starts maturing and your breasts will start filling. It is important to keep your breasts soft by feeding your baby regularly and expressing out breast milk if needed (2).


In summary what you need to remember, the more breast milk you remove, the more you will make. Also, that you have to be relaxed to promote breast milk to come down towards the nipple. Hope you enjoyed the read. Leave comments below.



  1. Guyton, A.C. & Hall, J.E.   Textbook of medical physiology.  Philadelphia: Elsevier Inc.
  2. South Africa. Department of Health.    Protecting, promoting and supporting exclusive and continued breastfeeding: a breastfeeding course for health care providers toolkit.  Pretoria.


No responses yet

Leave a Reply

Your email address will not be published. Required fields are marked *