Baby’s Lip Tucked While Bottle Feeding? How to Help
Is your baby' top lip rolling under when you give them a bottle, and you aren't sure why?
If the answer is yes, then this blog is for you. While on the spectrum of big problems, the top lip being rolled under doesn't rank high on the things to worry about list, having the lips flipped out can make feeding easier and more comfortable for your baby, especially if the rolled lips are happening becaue of tension around their mouth.
In this blog, I want help you understand why it happens so you can explore this yourself if this is a problem for your baby.
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Why Your Baby’s Lip Rolls Under
It’s super frustrating when—no matter what you do—your baby’s top lip keeps rolling under during bottle feeds. And you might be wondering: Does this even matter?
The answer is: it can matter.
Babies use the muscles around their mouth to help stabilize the bottle, and the seal between their lips and the bottle helps them create the vacuum they need to feed effectively.
When the top lip is rolled under, they can’t use those muscles well. It makes feeding harder.
Try it yourself—roll your lips under and try to swallow. It feels awkward, right? It's physically harder to move your tongue, and your mouth has to work a lot harder to compensate.
Whether or not this becomes a real issue depends on why your baby’s lip is rolling under in the first place.
There are three main reasons this happens:
The bottle nipple pulls the lip under as it’s going in—usually because of how it was offered.
There’s tension around the lips that makes it hard for the lip to flare out.
The muscles used for feeding aren’t well-coordinated yet, so baby’s using compensations instead of reflexive movement.
When the lips stay tucked under—or can’t flare out—the seal around the bottle doesn’t work as well. That can lead to leaking, swallowing air, or just a feed that takes more effort than it should.
The good news? It’s usually pretty simple to figure out why it’s happening—and once you do, you can start making changes that help.
Using the Gaping Reflex to Help
Full disclosure: this is my favorite thing to do with babies. The gaping reflex is, in my opinion, the most important—and least used—reflex babies have.
You can use the gaping reflex to help your baby open wide before the bottle goes into their mouth. And that does a few really important things:
It helps them open wide enough to get a deeper latch on the bottle.
It encourages them to use and soften their jaw muscles.
When a baby is chestfeeding or breastfeeding, they naturally use their reflexes to guide the feeding process. Those same reflexes are still there during bottle feeds—and they still matter. Here's a blog that explains moreabout how reflexes shape feeding, even when it's from a bottle.
Reflexes help your baby’s brain build connections to the muscles they’ll use for feeding and movement. Feeding plays a big role in developing those connections—so anytime you can support those reflexes, no matter how you’re feeding, it’s a good thing.
In this case, using the gaping reflex also helps make sure the bottle nipple goes into the mouth *without* dragging that top lip in with it. That’s key if you’re trying to avoid the rolled-under lip issue.
The Gaping Reflex In Action
The gaping reflex is cued by a touch to your baby's chin. In this video, you can see the baby respond to the cue by opening their mouth. It doesn't take a strong or forceful touch - contact on the chin is enough to cue the brain to open wide.
Use the bottle like your finger and rest it against your baby's chin.
Wait for your baby to open wide.
Rest the bottle nipple against your baby's chin.
Wait for your baby to open wide.
Then put the nipple inside your baby's mouth.
Important Note: I have my bottle positioned a little high in this sequence. You want the soft part of the nipple giving the cue - if you can.
Flipping the Lip to Help
You can also use your fingers to gently flip your baby's lip up after they’ve latched onto the bottle. While this can definitely help—and sometimes it's the easier option—there are a few things to keep in mind when going this route.
Flipping the lip up helps in the moment, but it doesn’t address why the lip was tucked under in the first place.
And sometimes with babies (and life), you’re just not in a space to address the “why.” You just need something to make feeding feel better—right now.
If using the gaping reflex isn’t working—whether for that feed or at all—then gently flipping the lip can be a helpful support.
Just one big caution: Watch for signs of tension. If your baby has a lot of white around their mouth, or if their lip feels thick, tight, or hard to flip, go gently. Watch your baby for any signs of discomfort or change.
If they’re already tense, you don’t want to add more tension. You want to help release it—so their lip can flip on its own.
A good rule of thumb: only move what moves easily. If it doesn’t, that’s a clue that tension might be part of what’s making feeding harder—and working on that will likely lead to a more comfortable, more effective bottle latch.
What to Do Next
Now that you’ve got a few things you can try, the next step is simple: experiment.
Play around with flipping your baby’s lip up and see if it helps them feel more comfortable while feeding. Do you notice less leaking? Do they look more relaxed? Is their face softer?
And just ask yourself: Does it make a difference at all?
If the answer is no—and your baby is feeding well—then there’s nothing to worry about.
But if the answer is no and your baby still seems to struggle with their latch, that’s a helpful clue. There might be something else going on under the surface. It could be that the bottle isn’t a great match, that your baby needs a little support for oral function, or that there’s some underlying tension making feeding harder than it needs to be.
Sometimes it just takes a few more pieces falling into place.
You’re on the right track. Keep experimenting. Keep listening to your baby. Keep asking questions. You don’t need to have all the right answers—you just need to be asking the right ones. And you are.
Want More Support?
If this blog was helpful, here are a few related posts you might like.
🔒 Expanded Access resources go deeper to help you solve your latching and feeding problems. Click here to learn more about what’s inside.
Frequently Asked Questions
Some babies’ bottom lips tuck inward because their lower jaw sits a little farther back. As your baby grows, their lower jaw may grow forward, and the recessed appearance may become less noticeable.
The muscles around the lips, tongue, and jaw can also affect how the lower lip rests. When those muscles are tense, the lip may stay tucked instead of relaxing outward. Gentle massage around the lips, cheeks, and jaw may help the area relax.
A tucked lip is not always a problem. What matters is whether it keeps your baby from closing their mouth comfortably or maintaining a steady seal while feeding.
If the tucked lip happens along with leaking milk, clicking, repeatedly losing suction, or difficulty feeding, it can be helpful to look at why the lip is tucking instead of repeatedly flipping it outward.
A little milk leaking out once in a while is not always a problem. What matters more is whether it happens during most feedings.
Leaking can happen when the milk is flowing faster than your baby can manage or when they get more milk in their mouth than they are ready to swallow. It can also happen when the bottle or nipple is not a good fit, or when your baby has trouble keeping a steady seal around the nipple.
The nipple level on the package is only a suggestion. Your baby does not automatically need a faster nipple because they reached a certain age. When the flow is too fast, you may also notice gulping, coughing, choking, pulling away, or milk spilling from the corners of their mouth.
Holding the bottle more horizontally and using paced bottle feeding can give your baby more time to manage the milk and breathe comfortably between swallows.
If leaking happens during most feeds, especially with coughing, choking, clicking, repeated loss of suction, breathing changes, or stressful feedings, having a feeding professional watch your baby eat can help figure out whether the issue is flow, bottle fit, positioning, oral function, or swallowing.
Clicking usually means your baby is repeatedly losing the seal around the bottle nipple and then trying to latch back on.
This can happen when the milk is flowing faster than your baby can manage, the nipple shape is not a good fit, or your baby is having trouble maintaining steady suction.
Sometimes changing the bottle angle, slowing the flow, or using paced bottle feeding helps. A slower nipple may give your baby more time to coordinate sucking, swallowing, and breathing.
An occasional click is not always a problem. What matters more is whether clicking happens during most feedings or comes with leaking milk, coughing, choking, gulping, pulling away, repeated loss of suction, long feeds, or concerns about weight gain.
If clicking happens often, having a feeding professional watch your baby eat can help figure out whether the issue is flow, bottle fit, positioning, suction, oral function, or swallowing.
About the Expert Avery Young, IBCLC, is an International Board Certified Lactation Consultant who has spent more than a decade helping parents and professionals understand their baby’s reflexes, build confidence, and make latching and feeding feel better. Read more about Avery →
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