Oxytocin: The Love Hormone
As we begin this month discussing the various different hormones that affect lactation, we have to start with oxytocin. I think oxytocin is most talked about when referencing “how to increase my milk supply?” or “how is milk made?” However, most do not actually understand how oxytocin affects the production of human milk.
What does it do?
Oxytocin is often referred to as the “love hormone” and its affects on sexual behaviors between men and women is what it is most commonly referred to. However, oxytocin does not just contribute to sexual arousal. Oxytocin is highly critical to milk production in lactating women. This hormone is a key contributor in the “let down” or milk ejection process (MER). The MER process is triggered when baby’s tongue stimulates nerve endings in the mother’s nipples sending signals to the brain, which causes several reactions. One reaction includes the release of oxytocin, which stimulates muscles in the breast. As referenced in Figure 1, milk is stored in the alveoli and lobules in the breast, which is covered with myoepithelial cells, a basket of muscles if you will. When oxytocin is released, this stimulates the myoepithelial cells to contract, pushing the milk from the alveoli, into the ducts, and out of the nipple. (1)
Figure 1: Description of the Female Breast Tissue & Ductal System (2)
With this said, it is important to note that oxytocin does not in fact “make” milk, but rather it causes the release of breastmilk.
How does it affect milk production?
So if you are anything like me, now knowing that oxytocin does not in fact “make milk”, you might be wondering then why are we so concerned about oxytocin? Whenever we read about increasing our supply, oxytocin is always at the top of the list. This is because “in order to make milk, we have to move milk.” Keep in mind that as our alveoli fill and get closer to “full” this signals to our body to slow down milk production. Therefore, the more readily available oxytocin is to create a letdown, the less full our breasts are, and then signaling that our body needs to produce more milk. This is why it is important to encourage the release of oxytocin to increase milk supply.
How can I encourage (or discourage) oxytocin release?
The primary action, which causes the release of oxytocin, is nipple stretching. Ideally, this is caused when baby begins to suckle at the breast or when we extract milk with our breast pump. There are some other ways that we can help encourage a letdown, or the release of oxytocin.
Kneading & Touching the Breast: Babies instinctually tend to begin to do this on their own. As we place baby’s hands on the breast, they will begin to rub and massage our breasts. This action assists in achieving a letdown or another letdown. Although, you can perform this too, whether nursing or pumping simply softly rub, touch, and massage your breast while extracting milk.
Tension & Stress: There are a lot of unknowns regarding stress or cortisol levels and the impact of oxytocin. However, it is believed that these hormones operate opposite each other. When mother’s stress increases it commonly is difficult to achieve a letdown. So relaxing, being physically comfortable, and focusing on our babies rather than other stressors can help minimize tension and stress, encouraging the release of oxytocin.
Physical Pain: Very similarly to stress, when nursing or pumping is very painful, it can be very difficult for our bodies to release oxytocin. If nursing or pump is uncomfortable, maybe even dreading the feeding, this can inhibit our ability to have a letdown. If baby’s latch is painful, you should seek help through a lactation specialist as soon as possible. Similarly, if pumping is painful, you need to seek advice from a specialist. Expressing milk, no matter the way, should not be painful and it can affect our milk supply.
Emotional Comfort: It is very common that when we are used to nursing our babies that we can sometimes have issues reacting to a breast pump. As the saying goes, “we love our babies, not our pump.” The presence of our babies, their smell, seeing them, touching them, all of these things assists in achieving a letdown. So if you are struggling with a letdown when utilizing a pump, sometimes looking at photos of our babies, smelling a piece of their clothing, etc. can help us achieve a letdown with our breast pump.
In final…
Keep in mind that oxytocin does not in fact “make milk”. It is important, however, to encourage an environment where our bodies will release oxytocin for this is required in order for our bodies to produce milk. All said and done though, the body does not produce milk because of the presence of oxytocin, but it produces milk, because oxytocin expels milk and the body makes more milk to replace it. When working to increase our supply, the more consistently our breasts our “empty” the more milk our bodies will produce.
Lauwers, J., & Swisher, A. (2020). Counseling the nursing mother: A Lactation Consultant’s Guide. Jones & Bartlett Learning.+
Technology, L. C. (2021, February 9). Optimal model systems for breast cancer research. Lifeline Cell Technology. https://www.lifelinecelltech.com/optimal-systems-for-breast-cancer-research/