Letdown reflex: what milk let-down feels like, and what to do when it is slow

The let-down reflex, often written letdown, is what makes your milk flow once a feed starts. HealthHub explains that when your baby suckles, the hormone oxytocin releases milk into the ducts and moves it towards your nipple. Some mums feel a tingle or a tightening in the breast. Others feel nothing at all, and the NHS says that is normal.

What happens during let-down

Your breasts store milk in small sacs. When your baby sucks, your brain releases oxytocin, the sacs squeeze, and milk is pushed along the ducts to the nipple. Cleveland Clinic says the same release can be set off by seeing, hearing or thinking about your baby, by touching your breasts, or by pumping. Its breastfeeding specialist puts it simply: without oxytocin, most of your milk stays in the breast.

So milk can arrive before a feed starts. The NHS says you may notice it letting down when your baby cries or when you have a warm bath or shower, and that this is normal.

What letdown feels like, and how to tell it is working

It varies a lot. The NHS says some women get a tingling that can be quite strong and others feel nothing. The Australian Breastfeeding Association lists other signs: a sudden fullness that can even hurt, feeling thirsty, and milk leaking from the other breast, because let-down happens on both sides at once. It also says many mums notice it less as their baby gets older.

Watch your baby instead of your breast. The NHS describes quick sucks changing to deep, rhythmic swallows as the milk flows, often with a pause while your baby waits for more. If your baby falls asleep before those deep swallows start, ask someone to check the latch.

What slows it, and what helps

HealthHub says stress can inhibit the let-down reflex. It also advises cutting down on caffeine and avoiding alcohol and tobacco, which can inhibit let-down as well. The Australian Breastfeeding Association adds pain, extreme tiredness and feeling self-conscious, for example feeding in public or pumping at work. It says a slow let-down may make your baby fuss at the breast, but your supply will not be affected.

Things that help, from the Australian Breastfeeding Association and Cleveland Clinic:

• Slow breathing, dropped shoulders and a warm drink before you start.
• A warm cloth on the breast for a short while, and gentle massage towards the nipple.
• Looking at your baby, or skin-to-skin contact.
• Feeding in the same spot each time, since the reflex can be conditioned.

Pain blocks let-down too, so get sore nipples or a hot, painful patch seen to. A painful patch with fever may be mastitis.

Let-down when you are pumping

A pump is less good at triggering let-down than your baby, the Australian Breastfeeding Association says. SGH's neonatal team suggests a quiet, warm place, slow deep breaths, warmth on the breast or a warm shower first, and gentle massage before you start expressing. Thinking about your baby helps. If your baby is in the neonatal unit, SGH says expressing near the cot or right after a visit may be easier, and a photo helps when you are apart.

Cleveland Clinic suggests smelling a piece of your baby's clothing or watching a video of them. To plan how much milk each bottle needs, try our milk feeding calculator.

When let-down is too strong

Some mums have the opposite problem. The NHS says the reflex can occasionally be so strong that your baby coughs and splutters, and that a midwife or breastfeeding supporter can help. In Singapore, call KKH Lactation Services on 6225 5554 or the NUH lactation hotline on 9722 0376, or see a lactation consultant who can watch a feed with you.

Frequently asked questions

What does let-down reflex mean?

It is the reflex that releases stored milk during a feed. Oxytocin makes the milk sacs squeeze, so milk flows to the nipple and your baby can drink it.

Is it normal not to feel let-down?

Yes. The NHS says some women feel nothing at all. Your baby's switch from quick sucks to slow swallows is the better sign that milk is flowing.

Why do I leak from the other breast while feeding?

Let-down happens in both breasts at the same time, the Australian Breastfeeding Association says, so the breast your baby is not on can drip or spray.

Can stress stop my milk letdown?

It can slow it. HealthHub says stress can inhibit the let-down reflex. The Australian Breastfeeding Association says a delayed let-down does not reduce your supply, and relaxing helps it come.

Related terms

• Expressing (Pumping): Taking milk out of your breasts by hand or with a pump, so your baby can have it later.
• Latch: How your baby attaches to the breast to feed. A deep latch takes in the areola as well as the nipple.
• Cluster Feeding: When your baby feeds again and again over a few hours, usually in the evening. Normal, and it builds supply.
• Mastitis: A painful, inflamed patch of breast, often infected, with fever and chills. Common in the first months of breastfeeding.
• Lactation Consultant (IBCLC): A breastfeeding specialist; IBCLC is the international credential. Helps with latch, pain, supply and pumping.
• Colostrum: The thick yellow first milk your body makes in the first few days after birth.

See every term in the glossary