More Resources What is oxytocin?

What is oxytocin?

Oxytocin is one of the key hormones (a brain chemical)  involved in the milk letdown reflex - It is the hormone responsible for getting milk from you to your baby. Oxytocin is sometimes known as the love hormone or 'cuddle' chemical because it can cause feelings of affection, love, and happiness. For breastfeeding or lactating moms, oxytocin does encourage feelings of affection towards their baby, which help with milk letdown.

The Limerick team, led by certified lactation consultants, has put together this short guide to what oxytocin is and what it does, based on information from the National Library of Medicine and CDC.

What is oxytocin?

Oxytocin is a hormone (a chemical messenger) produced in the hypothalamus in the brain. Along with the pituitary gland, the hypothalamus tells other glands throughout the body to produce hormones that affect your health.

Oxytocin is produced by the hypothalamus and secreted by the pituitary gland. It plays a key role in childbirth and in the lactation process. In women, oxytocin is responsible for signaling contractions of the uterus during childbirth. The hormone stimulates the uterine muscles to contract, which causes labor to begin, and increases the production of other hormones, which keep labor moving and increase contractions. This effect of oxytocin is why women who don't start labor naturally are sometimes given a synthetic form of oxytocin (Pitocin) to induce labor.

Studies of oxytocin have found that it plays a role in human social behaviors, and might also be involved in recognition, trust, anxiety, and sexual arousal, while other research has found that the hormone is also linked to stress. Among its main roles, however, is in milk letdown and encouraging feelings of affection between mom and baby.

Oxytocin after childbirth

Once your baby is born, oxytocin moves milk into your breast, ready for nursing. When the baby sucks at mom's breast, it triggers the release of oxytocin, which in turn causes milk to be released, so your baby can feed.

Oxytocin is also released into the brain to promote further oxytocin production while the baby feeds. When your baby stops nursing, the production of the hormone stops, and begins again at the next feeding.

How does oxytocin production work?

Oxytocin production is regulated by a positive feedback mechanism, which allows oxytocin to be released when a trigger is present. In other words, when your baby nurses (a trigger), the nerve cells in your nipple signal to your brain to release oxytocin. Oxytocin then causes the muscles in your breast to contract and squeeze breast milk into your milk ducts to be released. This cycle continues until your baby has finished feeding or until you've finished pumping.

Other effects of oxytocin

Oxytocin is not only responsible for milk release - it has many roles in the body. It is the hormone which causes your uterus to contract during labor, and to contract and shrink after childbirth. It's also been found to lower stress and anxiety, and it may play a role in protecting against postpartum depression.

Problems with oxytocin production

There is no clear medical research on the effects of high or low oxytocin levels. For breastfeeding women, low levels of oxytocin can prevent the milk ejection reflex. If you're concerned about milk letdown, speak with your lactation consultant. Often the problem is easily solved, but the consultant will let you know whether you should see an endocrinologist.

Problems with milk letdown

Oxytocin is crucial for milk ejection, and oxytocin is also intrinsically linked to mom's mood and how comfortable she feels. While oxytocin release can lead to feelings of maternal affection, if you feel anxious or upset about something, these feelings can prevent its release in the first place. A number of factors can prevent oxytocin release, such as severe stress.

It's important to feel comfortable before you start to pump or breastfeed your baby. Try to relax; it might help to take a few deep breaths (in through the nose, then slowly out through the mouth). You could also try listening to some relaxing music, or looking at a photograph or video of your baby if you can't be physically close to them. Limerick breast pumps include positive affirmations, which can help moms to relax and feel comfortable before and during a pumping session.

If you have a health condition or illness which may be affecting your milk production, speak with your lactation consultant or healthcare provider.

Factors that may affect oxytocin release

A number of factors may interfere with the release of oxytocin, and so may affect your milk letdown:

  • Pain
  • Breast surgery - when the nerves in your nipple have been severed, the signal usually sent to your brain may be prevented
  • Stress or anxiety - the hormones released during the stress response can prevent oxytocin release
  • Fatigue
  • Illness
  • Fear or embarrassment
  • Drinking alcohol
  • Smoking

Factors which may improve oxytocin levels

Oxytocin increases feelings of calmness and reduces stress and anxiety by lowering levels of your body's main stress hormone, cortisol. Feeling relaxed is essential when pumping or breastfeeding. There are some factors that can help to increase oxytocin levels in the brain.


Vitamin D

Vitamin D is made by your skin when exposed to the sun, though it is also found in some food items, such as dairy products. Every tissue in our bodies has vitamin D receptors, so deficiencies can lead to problems with hormone production.

Vitamin C

Vitamin C is a cofactor in the production of oxytocin; in other words, oxytocin is dependent on vitamin C. Include plenty of fruit and vegetables in your diet, particularly those which are bright red/purple or green, like peppers, tomatoes, citrus fruits, and leafy green vegetables.


Magnesium is present in hundreds of biochemical reactions in our bodies, including oxytocin. Make sure you include magnesium-rich foods in your diet, such as spinach, chard, cashew nuts, pumpkin seeds, almonds, avocado, bananas, and even dark chocolate (in moderation!).


Managing stress levels can help encourage oxytocin release since oxytocin is linked to mood. Activities such as meditation, yoga, and listening to music can help reduce stress. Additionally, socializing is important because it can reduce stress at home and increase feelings of social bonding.