Baby Sucking on Lower Lip – Is It Bad?

By Maria Wilcox •  Updated: 10/31/22 •  9 min read
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Does baby sucking on their lower lip have you a bit worried? Don’t worry, mom and dad. This type of behavior is normal and common in babies. Still, it helps to know why your baby is sucking on his or her lips. What are the potential outcomes could be if the sucking continues? Join us as we delve into why your baby may be displaying this behavior and what, if anything, you can do about it. 

Why Does My Baby Keep Sucking on His Lower Lip?

The reasons behind why babies suck on their lower lips are plentiful.

While we couldn’t possibly give an explanation for every reason of baby’s lips sucking, we have listed below a few of the most common culprits for bottom lip sucking. 

baby sucking on lower lip

These include:

  • Teething – Sometimes teething is the culprit for a baby sucking on the lower lip. As budding teeth apply painful and uncomfortable pressure on your baby’s gums, it’s natural for your little one to try and soothe that pain. Besides chomping on his or her fists and toys, you may find your baby sucking on their lower lip to provide their gums with a little added comfort. 
  • Stress – Sometimes a baby that is overstimulated or stressed for other reasons may start biting his or her lips. If the lip sucking or biting is accompanied by crying, or if you know that your baby has been in a stressful situation, try removing your baby from his or her current environment. Place them somewhere that is quiet and free from stimuli. Note: Remember that some things that your baby may find stressful, you may not. For example, attending parties or staying up late at night may be a hoot for you. But for your little one, it may prove too much. Always avoid overstimulating your baby (especially your newborn) whenever possible.
  • Boredom – Just as your baby can become overstimulated, it may be that your baby becomes under-stimulated too. If your baby becomes bored, he or she may begin to fidget. Or, you guessed it, begin to suck their lips. This may be a convenient way for your baby to pass the tim.e It generally isn’t anything to worry too much about.
  • Sucking Reflex – Babies are born with a “rooting” or “sucking” reflex which makes it so that they’ll open their mouths and turn their heads towards anything that touches the corner of their mouths. This is for feeding purposes, however, because a baby has a natural inclination to want to suck, he or she may find that sucking their own lips when mom’s nipple or a baby bottle isn’t available is an easy and accessible option. 
  • Milestones – As your baby grows, he or she will grow leaps and bounds both mentally and physically. As new neuro connections form in your baby’s brain, you may find that he or she may start sucking their lips in response. Moreover, your baby may also suck his or her lips in order to practice chewing, which is yet another important milestone for babies who start solid foods around 6 months and up. 

Related Read: Baby Chewing on Tongue

Baby Sucking on Lower Lip By Age

Sometimes, the reasons for your baby sucking on his or her lower lip will vary by age.

Here are a few of the most common reasons your baby may be sucking his or her bottom lip at specific months during infancy:

3 Month Baby Biting Lower Lip

If your three-month-old is biting his or her lower lip, it could be a sign of stress. Or it could be the rooting reflex we talked about earlier.

Think a 3-month-old can’t still have his or her sucking reflex? Think again! Some babies can go as long as 3-4 months before their rooting reflex disappears! 

4 Month Baby Biting Lower Lip

A four-month-old baby biting lower lip could be indicative of teething or general exploration.

It is between the ages of 4-6 months that babies really start exploring with their mouths. This continues on for a while and can even continue into toddlerhood.

As your baby grows, you’ll notice that he or she will begin to explore the world around them. They do so by mouthing almost anything they come in contact with. And because their lower lip is easily accessible, you may find your baby sucking his or her lower lip just for fun! 

5 Month Old Keeps Biting His Lower Lip

If your 5-month-old keeps biting or sucking his or her lower lip, it may be an indicator that teeth are pushing through.

While some kiddos may start teething as soon as three months, most babies don’t start teething until they are between 4-7 months old. It is for this reason that your baby’s sucking could be directly linked to the fact that his or her teeth are pushing through. And it could be that your baby is trying to relieve that pressure.

To help, allow your baby to gnaw on your (clean) finger. Or you could try purchasing natural organic rubber teething toys to help lessen the pain.

Baby Finger Toothbrush for Training Teething - Infant & Toddles & Lids Teeth Brush Soft Babies Toothbrushes Oral Cleaning Massager to Train Your Child Healthy Oral Habits -3 PCS

6 Month Baby Biting Lower Lip

At six months old a baby sucking or biting on the lower lip could be linked to multiple causes.

First and foremost, it is around this age that your baby can begin being introduced to solids. Around this time, you may notice your baby gumming or sucking at his or her lips as practice for chewing. Some parents even notice their babies doing this at mom and dad’s meal times. Whatever the case, many babies do this between 4-6 months old and it shouldn’t be any cause for worry. 

Other reasons for a six-month-old biting his or her lips include fatigue, stress, and yes, teething. If your baby does this often and it leaves his or her lips raw or inflamed, it may be time to reach out to a pediatrician for help.

A Surefire Sign Your Baby Is Biting Lower Lip

Most of the time, if your baby is sucking his or her bottom lip, you’ll see it. But there also may be times when your baby does this, like while sleeping or resting, when you may not notice it.

If your baby develops a red or pink ring around the bottom of his or her lower lip, it is a surefire sign that your baby is sucking his or her bottom lip at times when you may not notice. 

baby sucking on lower lip

How to Stop Baby Biting Lower Lip

In most situations, a baby that bites or sucks his or her lower lip isn’t at risk.

The lip sucking is usually a temporary phase that most babies grow out of.

Still, for babies that don’t outgrow the habit or for babies that suck their bottom lip too much, it is possible that the baby may develop speech concerns. Or they may develop damage done to their teeth and gums. 

While these instances are extremely rare, if you notice that your baby keeps sucking or gumming at their lips and it is causing the skin on and around the mouth to go raw, you may be able to try the following:

  • Feed Your Baby on Time
  • Remove Your Baby From Excess Stimuli
  • Alleviate Teething Problems Using Appropriate and Safe Teething Toys
  • Use a Pacifier
  • Use Natural Oils to Soothe Rash

Baby Tucking in Bottom Lip Breastfeeding

Oftentimes, when babies latch onto the breast for nursing, their lower lip tucks in while the top lip stays out. This is a normal occurrence in babies. However, it can lead to painful and sore nipples if not corrected.

To remediate the issue, simply use your thumb to gently tug your baby’s chin in a downward motion while they are sucking. This will release his or her lower lip so that it flips back out, rather than being tucked in. This remedy will lead to a better latch, easier extraction of milk, and also, 


Baby sucking on upper lip…what does it mean?

Rest assured that a baby sucking on the upper lip is no cause for worry. While older generations have attributed this behavior as meaning the baby will soon fall ill, we now know that a baby sucking his or her top (or bottom) lip is simply an indicator that they are teething, hungry, or that your baby is soothing themselves. And although a baby sucking his or her upper lip is totally normal, you should always follow up with a pediatrician if your baby’s behavior ever concerns you or causes negative effects on his or her growth and development.

baby sucking on lower lip

Baby Sucking on Lower Lip? Completely Normal!

If your baby is sucking on his or her lower lip, there generally isn’t a need for concern. Babies do this for various reasons including teething, boredom, hunger, and stress.

To remediate the issue, try to ensure that your baby is fed on time, that you give them plenty of rest, and that you give your baby teething toys to chew on to help relieve the pressure felt in their gums during teething.

We hope this helps! 

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Maria Wilcox

Former instructor with an M.A. in Education turned grateful stay-at-home mama to one, I look to share helpful insights related to babies, toddlers, kids, and families for the benefit of real people just like you.

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