How Breastfeeding Works: Understanding Your Body’s Amazing Milk-Making Process

Breastfeeding: A Partnership Between You and Your Baby

Breastfeeding is often described as natural - and it is - but it’s also a finely tuned process between your baby and your body. Understanding how milk is made, how hormones like prolactin and oxytocin work, and why frequent feeding matters can help you feel more confident, especially in the early days.

Think of breastfeeding as a dance between your body and your baby: your baby signals the need, your body responds, and together you create a rhythm that supports both nourishment and connection.

The Two Key Hormones: Prolactin and Oxytocin

Prolactin: The Milk-Making Hormone

Every time your baby breastfeeds (or you express milk), your body releases prolactin. This hormone tells the milk-producing cells in your breasts (called alveoli) to make more milk for the next feed.

• Prolactin levels rise most when your baby suckles directly at the breast.

• They peak at night, which is why night feeds are so important for maintaining supply.

• Prolactin works on a “next feed” system - the milk your baby removes now triggers the production of more milk for later.

Oxytocin: The Milk-Releasing Hormone

Oxytocin is sometimes called the “love hormone” because it’s also released when you hug, touch, or connect with someone you love. During breastfeeding, oxytocin causes the muscles around your milk-producing cells to contract, pushing milk down the ducts and out through your nipple.

This process is called the let-down reflex (or milk ejection reflex).

You might notice:

• A tingling or prickling sensation in your breasts

• Sudden leaking from the opposite breast

• A wave of relaxation or even sleepiness

Not everyone feels these sensations, and that’s completely normal - milk can still be flowing even if you don’t notice a “let-down” feeling.

The Let-Down Reflex in Action

When your baby suckles:

1. Nerves in the nipple send signals to your brain.
   

2. Your brain releases oxytocin into the bloodstream.
   

3. Oxytocin tells the muscles around milk cells to contract.
   

4. Milk is pushed into the ducts and flows to your baby.
   

This reflex can also be triggered by hearing your baby cry, thinking about your baby, or even during skin-to-skin contact. Some parents experience multiple let-downs during a feed.

Tip: If you’re expressing milk, looking at a photo or video of your baby can sometimes help trigger let-down.

Supply and Demand: The Secret to Milk Production

One of the most reassuring things to know is that milk supply works on a supply-and-demand basis.

• The more often milk is removed, the more your body will make.

• If milk isn’t removed regularly (for example, if feeds are spaced out or skipped), your body gets the signal to slow down production.

• This is why frequent feeding or regular pumping is important, especially in the early weeks.

Your body is clever - it adjusts production based on your baby’s needs. Growth spurts, cluster feeding, or increased expressing all tell your breasts to step up milk production.

Common Questions About Breastfeeding and Let-Down

What if I don’t feel a let-down?

Not everyone feels the let-down reflex. As long as your baby is having plenty of wet and dirty nappies and gaining weight well, your milk is flowing just as it should.

Can stress affect let-down?

Yes. Stress, pain, or anxiety can interfere with oxytocin release and make let-down slower. Simple calming measures — skin-to-skin with your baby, deep breathing, or a warm compress — can help.

Why do my breasts leak when I’m not feeding?

That’s spontaneous let-down! Oxytocin release can be triggered by thinking of your baby, hearing them cry, or even by the sound of another baby crying. Many parents use breast pads in the early weeks until supply balances out.

Can I have too many let-downs?

Some parents experience very strong or frequent let-downs, leading to fast milk flow. This can make babies cough or gulp. Feeding in a laid-back position or expressing a little milk before a feed can help slow the flow.

Supporting Your Milk Supply

Here are some gentle ways to encourage your body’s natural milk-making rhythm:

• Feed often: Aim for 8–12 feeds in 24 hours for newborns.

• Offer both breasts: Not every feed needs both, but alternating sides helps balance supply.

• Night feeds matter: Prolactin peaks at night, so feeding overnight helps keep supply strong.

• Stay close: Skin-to-skin contact boosts oxytocin and helps trigger let-down.

• Avoid long gaps: Skipping feeds or replacing them with formula without expressing may reduce supply.

If you’re concerned about supply, check in with an IBCLC (International Board Certified Lactation Consultant) or your midwife for personalised support.

When to Seek Support

While breastfeeding is natural, it’s not always easy. If you notice any of the following, reach out to a health professional:

• Baby isn’t gaining weight or has fewer than 5–6 wet nappies per day after the first week

• Persistent nipple pain or damage

• Recurrent blocked ducts or mastitis

• Concerns about oversupply or very forceful let-down

You don’t need to navigate these challenges alone - early support can make a big difference.

Bringing It All Together

Breastfeeding is more than just milk-making - it’s a dynamic process shaped by your body, your baby, and the hormones prolactin and oxytocin. Every feed is an exchange of signals: your baby’s suckling tells your body to release milk now and make more for later.

Understanding how breastfeeding works can make the journey feel less mysterious and more empowering. Whether you feel your let-down or not, whether supply feels abundant or uncertain, your body is responding to your baby in incredible ways.

Remember: every breastfeeding journey is unique. Trust your instincts, lean on your support network, and don’t hesitate to seek help if you need it.