Hyperlactation: are you really making “too much milk”?

During breastfeeding, true hyperlactation is much rarer than people tend to think. In most cases, a high milk supply reflects lactation that is still adjusting, a temporary oversupply or a strong let-down reflex — not a medical condition. Diagnosing hyperlactation relies on a combination of signs in both mother and baby, never on the amount of milk pumped alone.

• Hyperlactation is defined as a milk supply that is consistently higher than the baby’s needs, with consequences for the mother, the baby, or both.
• In the first few weeks, an abundant supply is most often physiological: lactation gradually adjusts to the baby’s needs.
• Before trying to reduce supply, it is important to have the situation assessed by a professional trained in breastfeeding support.
  

Breastfeeding: am I making too much milk?

A baby who chokes at the breast, heavy leaking, breasts that stay very full, or a breast pump that collects large amounts of milk… It is not unusual to hear: “You must have hyperlactation.”

Yet this is often just a milk supply that is slightly higher than the baby’s needs, without it being a medical condition. Before trying to reduce milk production, it is therefore essential to understand what hyperlactation really is.

What is true hyperlactation?

Protocol No. 32 from the Academy of Breastfeeding Medicine (ABM, 2020) defines hyperlactation as a milk supply that is persistently higher than an infant’s needs, leading to consequences for the mother, the baby, or both.

In other words, a mother pumping a lot of milk or having very full breasts does not mean she has hyperlactation. The diagnosis is based above all on the overall clinical picture.

Is milk supply stable from the first few days?

No. Contrary to what people sometimes imagine, milk supply does not settle immediately after birth.

In the days following birth, the onset of milk production (called lactogenesis II) is triggered by the hormonal changes of birth. Over the following weeks, supply remains strongly influenced by hormones. Breasts can be very large, tense and sometimes uncomfortable. Leaking is common, and it is possible to express large amounts of milk. That does not necessarily mean the mother is producing “too much” milk.

Gradually, as feeds go by, lactation becomes more controlled by the amount of milk removed from the breast. Supply then adjusts to the baby’s needs. For many women, this balance is established between 4 and 8 weeks, sometimes a little later. This adjustment period is completely physiological. 

Is a temporary oversupply the same as hyperlactation?

No. Some mothers do produce a little more milk than their baby drinks… but only for a few days or a few weeks. This may show up as:

• breasts that often feel very full;
• heavy leaking;
• a baby who gains weight quickly;
• some spit-up or regurgitation;
• a baby who drinks very quickly at the start of a feed.

In most cases, this situation settles on its own as milk supply adjusts to the baby’s demand. It is not true hyperlactation.

Strong let-down reflex and hyperlactation: what is the difference?

It is common to confuse milk volume with milk flow rate. Some mothers have a strong let-down reflex (SLR): milk flows too quickly for the baby at the start of the feed. The baby may then:

• pull off the breast;
• choke;
• cough;
• swallow quickly;
• ask for pauses.

Even so, the total amount of milk produced may be completely normal. A strong let-down reflex is therefore not the same as hyperlactation.

What are the signs of true hyperlactation?

The diagnosis is based on the overall clinical picture, in both mother and baby.

In the mother

• repeated breast engorgement;
• recurrent mastitis;
• repeated blocked milk ducts;
• pain linked to significant breast fullness;
• a constant feeling of breasts being too full despite feeds, with production that can reach 2 to 2.5 litres per day, or even more.

For comparison, a mother who exclusively breastfeeds usually produces between 750 and 1,200 mL of milk per 24 hours 

In the baby

• weight gain that is sometimes very rapid, above 1.5 to 2 kg per month;
• very abundant and sometimes greenish stools;
• difficulties managing milk flow;
• restlessness at the breast.

These signs should always be interpreted in context. To learn how to assess your baby’s growth and intake, read our article “Is my baby getting enough milk?”.

Why is hyperlactation talked about so much?

Over the past few years, the term has become very common. Yet true hyperlactation remains uncommon. There is no precise prevalence figure, but the available publications agree that this is a relatively rare situation in the general population.

In practice, many women receive this diagnosis when their lactation is simply still adapting. Others have a strong let-down reflex, use their breast pump a lot, or inadvertently stimulate supply through very frequent pumping. The risk is then trying to reduce a supply that was in fact suited to the baby’s needs.

What causes a very high milk supply?

There is not just one way to have a very high milk supply. You may come across:

• Temporary oversupply: in the first few weeks, the body may still produce “too much” milk while it gradually finds its balance with the baby’s needs. This situation, sometimes wrongly called hyperlactation, often improves on its own over time.
• Hyperlactation maintained by stimulation: sometimes supply is unintentionally stimulated by frequent pumping, repeated milk expression or certain products aimed at increasing lactation. The more the breast is stimulated, the stronger the signal to produce milk.
• Primary hyperlactation: less commonly, supply remains very high despite appropriate stimulation. This is called primary or idiopathic hyperlactation when no obvious cause is found.

Can a breast pump maintain oversupply?

The breast works on a simple principle: the more milk is removed, the more it gets the message to make more.

Very frequent pumping, done without medical need or in addition to effective feeds, can gradually increase supply. Some mothers think they need to “empty” their breasts after every feed, when in fact this may, for some, maintain an excessive supply.

On the other hand, when a breast pump is used for low milk supply, to maintain lactation or to build a stash before returning to work, these pumping sessions serve a specific purpose. It all depends on the context.

What I see in consultations

It is not uncommon for mothers to come in worried, convinced they have hyperlactation because they collect 250 or 300 mL with a breast pump.

Yet a large amount of expressed milk is not enough on its own to make a diagnosis. Some women respond very well to the breast pump without producing more than needed, while others express little milk despite having a perfectly sufficient supply.

In consultation, the assessment focuses above all on the whole dyad: the baby’s behaviour at the breast, growth, feed frequency, breast condition, any complications and the mother’s experience. The aim is to distinguish true hyperlactation from a simple physiological variation or a temporary adjustment period.

Lucie Frappeau, IBCLC lactation consultant

What are the myths about hyperlactation?

“I have a lot of milk, so I have hyperlactation.”

False. An abundant supply can be completely physiological, especially during the first few weeks.

“My baby chokes at the breast, so I must be making too much milk.”

Not necessarily. A strong let-down reflex can explain these difficulties even when there is no oversupply.

“I pump 300 mL, so I have hyperlactation.”

The volume collected with a breast pump cannot, on its own, diagnose hyperlactation.

Did you know?

The human body does not know how to produce “just enough” from the very first days. As with many physiological mechanisms, there is a safety margin. Producing a little extra milk at the beginning helps meet the infant’s growing needs before lactation gradually adjusts through feeding.

A temporarily abundant supply is therefore often a sign that lactation is settling in, not a pathological condition.

When should you see a breastfeeding professional?

It is recommended to see a breastfeeding professional (IBCLC lactation consultant, midwife, doctor) if:

• you are suffering from repeated engorgement, mastitis or blocked ducts;
• your baby is very unsettled at the breast or has trouble feeding calmly;
• the discomfort affects the comfort of feeds or your breastfeeding experience;
• you are considering changing your milk supply before the situation has been assessed.

Early support helps avoid unsuitable measures: a sudden reduction in supply, stopping the breast pump, or, on the contrary, unnecessary extra pumping.

What if you need to pump your milk?

When pumping is recommended, for example when returning to work or being separated from your baby, the aim is to pump on a set schedule with a professional, without unnecessary extra stimulation. Adjustable equipment helps keep pumping comfortable: the portable breast pump Emy Pump offers several flange sizes and adjustable suction to adapt pumping to your situation.

Learn more about Emy Pump

Key takeaways

• True hyperlactation is relatively rare: many situations are actually temporary oversupply or lactation that is still adapting.
• The diagnosis is based on a set of signs in both mother and baby, not on how much milk is pumped.
• Before trying to reduce supply or changing pumping habits, it is important to have the situation assessed by a breastfeeding professional.