Lactose Overload in Babies: Yes, Too Much Milk Can Be a Problem!
When it comes to milk supply, there’s a common assumption that more is better. But here’s the truth that isn’t talked about enough: having too much milk can be just as disruptive as not having enough.
Oversupply and forceful letdowns can wreak havoc on both mum and baby, and yet so many mothers are told to just “be grateful” they have plenty of milk. Let’s be clear: this isn’t about gratitude. This is about comfort, function, and feeding that actually works for both of you.
What is Lactose Overload?
Lactose overload happens when your baby gets too much milk too quickly, usually due to a combination of oversupply and a fast letdown. It’s not about “too much foremilk”, that theory is outdated. Here’s what’s really going on:
Breastmilk contains lactose (milk sugar) in fairly steady amounts throughout a feed, but fat content increases gradually as the feed progresses. Fat plays an important role in slowing digestion, helping your baby’s gut break down and absorb lactose properly.
When milk volume is high and feeds are fast, babies often receive large amounts of milk before they've had a chance to access the milk that’s higher in fat. This rapid milk intake means:
Milk moves too quickly through the gut
Lactose doesn’t get enough time to be digested
Undigested lactose ferments in the lower bowel
Cue: wind, pain, explosive nappies, and unsettled feeds
Signs Your Baby May Be Struggling With Oversupply or Lactose Overload
These babies often look hungry and overfed at the same time because they’re trying to regulate things the only way they know how: by sucking for comfort which can lead to feeding (and feeding, and feeding). Here's what it can look like:
Explosive, runny, frothy, mucusy, or frequent greenish poos (can have a vinegary smell or still be ‘sweet’ smelling
Excessive gas, tummy cramps, straining, or knees-up discomfort
Hiccups, coughing, choking or gulping at the breast
Pulling off, clicking, or fussing during feeds
Vomiting (often large volumes), sometimes out the nose
Short, frantic feeds or feeding constantly to self-soothe
Poor sleep due to gut discomfort
Colicky and/or refluxy (including silent reflux) symptoms
Large and rapid weight gains every week (over 300-400grams each week)
What It Feels Like for Mum
It’s not just the baby who struggles. Mothers with oversupply often experience:
Engorgement and uncomfortable, lumpy breasts
Blocked ducts or recurrent mastitis from incomplete drainage
Letdown pain or spraying milk during and between feeds
Leaking constantly, sometimes needing multiple breast pads per day
A baby who seems fussy, restless, or never quite satisfied
A mental load that says “you’ve got heaps of milk, so what’s the problem?”
And that last one? It hurts. Because the struggle is real, even if you’re not “running dry.”
Why Too Much Milk Isn’t Always a Gift
Oversupply sounds like a nice problem to have, until you're sleep-deprived, soaked in milk or struggling with frequent blocked ducts, engorgement or recurrent mastitis whilst holding a distressed baby who’s crying from gas pain and vomiting up feeds.
Milk that comes too fast and too often doesn’t give babies the chance to:
Learn to suck effectively
Coordinate their suck, swallow and breathing - leading to frequent oesophageal and/or nasal regurgitation
Feel satisfied and content that their sucking need has been met after a breastfeed
Feel safe and settled at the breast
It’s a bit like trying to drink water from a fire hydrant. It’s not exactly nourishing, you feel so bloated, heart rate is racing and just overwhelmed.
What Can Help?
You don’t need to just “ride it out.” Oversupply is treatable, and so is lactose overload. This type of support should always be under the guidance of an IBCLC and might include:
Full Drainage Method + Block feeding - Temporarily expressing to reset supply, then offering one breast per feed to reduce overstimulation and give baby time to learn how to suck properly again.
Feed Positioning Adjustments - Upright positions, laid-back breastfeeding, or side-lying can help slow the flow.
Oral Function Assessment - Babies with ties or poor tongue control and elevation may be more vulnerable to dysregulated feeding. So, it’s worth checking if baby is actually able to manage your supply.
Responsive Feeding with Flow Awareness - Watching your baby, not the clock. Depending on your supply, some babies may get what they need really quickly (in approximately 4-6 minutes). Imagine, how we feel when we scoff our food down though? Not a pleasant feeling. Therefore, helping your baby pace themselves with breaks during feeds and some comfort sucking (either with your finger or pacifier) for short periods can help support their digestion.
IBCLC Support - Because you deserve someone who understands lactation and infant behaviour, not just a shrug and a “you’ve got plenty of milk!” or “your baby gaining this rapid weight is a good sign” when they’re visibly so uncomfortable.
The Bottom Line
Oversupply isn’t just an “annoying” issue. It’s a real feeding dysfunction that deserves support, not dismissal. If your baby’s feeds are chaotic, vomity, uncomfortable, or just don’t feel right, trust your gut and reach out. A regulated milk supply supports a regulated baby.
And remember, just because your body makes a lot of milk doesn’t mean it’s all working well!
If you’re considering strategies like the Full Drainage Method, block feeding, or adjusting feeding times, these should always be done under the guidance of an IBCLC. Why? Because while these tools can be incredibly effective, they can also trigger unintended drops in supply, weight concerns, or mastitis if done without proper support. A personalised plan makes all the difference.
You deserve help that looks at the full picture - your supply, your baby’s feeding function, and your wellbeing, too!
Need Support?
If you suspect your baby might be dealing with lactose overload or you’re navigating oversupply and fast letdown, you’re not alone and you don’t have to figure it all out by yourself!
📅 Book a lactation consultation in Perth or via Telehealth with The Gentle Village here to get tailored support from IBCLC’s and endorsed midwives who gets it.
🎥 Want to see what lactose overload can actually look like in a baby? Check out our reel on Instagram:
👉 Watch here