What Are Bottle Liners Used For? (& Why You Need Them!)

Balint Horvath, PhD

Writer, parent, and veteran of baby feeding battles.


If there’s one thing that frustrates bottle-feeding parents the most, it must be the seemingly endless task of cleaning bottles! Do you ever wonder what bottle liners are used for and if they offer an alternative to spending less time at the kitchen sink washing dirty baby bottles? The concept certainly sounds like a smart solution!

Baby bottle liners are often used to reduce symptoms associated with colicky or fussy babies. Disposable liners can be used to reduce the washing of bottles especially while traveling or to save time at home. Liners can be used in place of anti-colic bottles with venting systems.

Key takeaways

  • Bottle liners act as an insert preventing contact between the milk or infant formula and the bottle interior. 
  • Baby bottle liners can be used to prevent colic or gas, when you’re traveling away from washing facilities or using standard bottles without venting systems. 
  • Liners for baby bottles aren’t a necessity but they can come in handy on some days!
  • Eight to 10 reusable bottle liners are sufficient for regular feeding while a new disposable liner should be used for every feed.
  • Baby bottle liners are made from soft plastic free of toxic chemicals such as BPA.
  • The biggest health concern of using liners is the leaching of chemicals from the plastic into the content. 
  • Bottle liners can be used for both formula and breast milk.
  • Fussy babies will benefit from drinking from bottles with inserts that help to reduce the risk of gas. 

What Are Bottle Liners? 

Baby bottle liners are specifically designed to keep the contents such as breast milk or infant formula in a pouch-like bag or insert that fits inside the bottle. Disposable bottle liners are pre-sterilized. Pediatricians may recommend using bottle liners if your baby battles colic or gassiness. 

Here’s how the bottle liner called Playtex Baby Nurser Bottles Drop-Ins looks like.

Playtex Baby Nurser Bottles Drop-Ins Recyclable Disposable Liners, Pre-Sterilized, 4 Oz, 50 Count

Bottle liners contract during feeding, reducing the amount of air mixing with the milk or infant formula helping reduce colic symptoms.

They have another use, too. Using liners can also reduce the amount of time spent washing bottles especially if you use disposable products. 

How Are Bottle Liners Used? 

Resembling a thin-walled bag or pouch, the liner is inserted into the bottle before filling it with milk or formula. They can be disposable or reusable and can be used for the following reasons:

  • Reduce fussiness: Bottle liners imitate breastfeeding, contracting when your baby feeds. This reduces symptoms associated with colicky or gassy babies, which starts typically when babies are 6 weeks old and lasts until they’re about 4 months old
  • Traveling: If you don’t have access to clean water for washing bottles while traveling, inserting disposable liners makes it easier to bottle feed your baby while on the move. 
  • Replace venting systems: Liners can be used in standard baby bottles without venting systems. They can be used when you want to stop using the Dr. Brown vent if you’ve been using this brand bottle for feeding your baby. 

Disposable liners are time-savers at home too, on those days when you don’t have time to wash bottles. It also means you can prevent the build-up of mold in the bottle.

Here’s a review video showing the Playtex Bottle Drop-Ins. One thing to be aware of is that it works only with Playtex bottles. Later I’ll mention also other brands which sell liners that are compatible with a number of popular brands.

Do You Need Baby Bottle Liners? 

Bottle liners aren’t an absolute necessity but keeping stock on hand is useful if your baby’s anti-colic bottle suddenly breaks or you’re spending a day out and about or as an alternative to sterilizing it when staying in a hotel. They can be used by caregivers such as grandparents who don’t want to fuss with washing bottles. 

Bottle liners save you the hassle of washing various parts that come with a venting system such as tubing and valves. However, anti-colic bottles are your best solution for fussy babies with liners acting as a standby for unexpected eventualities

How Many Baby Bottle Liners Would You Need? 

The number of baby bottle liners you need depends on what you’re using them for. If you’re using them to reduce colic or gas while bottle feeding, reusable liners are recommended. You’ll need between 8 to 10 liners, ensuring you have a clean one for every feed. 

If you’re using disposable liners while traveling, you’ll need one clean bottle liner for every feed. The total quantity can be calculated by the number of feeds you’ll be giving your baby while on the road or while having no access to washing facilities

What are Bottle Liners Made From? 

Top baby brands ensure that the bottle liners are made from non-toxic soft, flexible, clear plastic, free from BPA, phthalates, and PVC. Other toxic chemicals such as lead and mercury shouldn’t be present in bottle liners. Always read the packaging label before purchasing bottle liners to ensure they’re free of any toxic agents. 

Are Bottle Liners Safe?

Yes, baby bottle liners are safe because they’re made with safe materials. 

In the past, the main health concern of using plastic baby bottles or liners was the presence of Bisphenol A (BPA) which can leach into the milk or formula especially when heated. Health side-effects of BPA exposure include:

  • Weakened immune system
  • Obesity
  • Early onset of puberty
  • Hyperactivity
  • Increased risk of cancers

However, BPA has been banned from all baby bottles and liners in the USA since 2012 but always check the packaging label to make sure the product is BPA-free. The biggest health concern is heating the contents in liners at extreme temperatures. This can cause other chemicals in the plastic to leach into the milk or formula. 

Watch this video which talks about the risk of BPA in plastic baby bottles.

Can You Use Baby Bottle Liners with Formula? 

You can use baby bottle liners with formula but manufacturers do recommend not heating them at high temperatures. This prevents contamination of the formula with chemicals found in the plastic liners. 

When using a liner, scoop the formula into the insert and add water heated up in a separate container before shaking and feeding your baby. Keeping hot water in a flask is useful for those days you’re traveling and using bottle liners. 

Can You Use Baby Bottle Liners with Breast Milk? 

Bottle liners can be used with breast milk and the action resembles breastfeeding, making it a suitable option when switching to a bottle. The same precaution as for heating formula should be taken when using bottle liners for breast milk. 

Using baby bottle liners is a good way of introducing your breastfed baby to the bottle without increasing the risk of colic, reflux, or gas.

Can You Use Bottle Liners with Any Bottle?

Not all types of bottle liners will work in other types of bottles. For example, Playtex bottle liners are specifically designed for Playtex bottles. So when you purchase baby bottle liners you should check its compatibility with the bottle brand’s you’re using.

Check both regular bottles and in the end also anti-colic ones so you can decide if you should go for a bottle liner or for the real deal – a bottle with specially design anti-colic features.

MOTHER-K disposable baby bottle liners work with many brands which you might want to check out.

Do Baby Bottle Liners Reduce Gas?

Intolerance to certain formulas and the presence of gaseous foods such as some vegetables in breast milk can result in a gassy baby! One of the other biggest causes of baby gas is swallowing too much air while feeding. 

When looking at the Dr. Brown or MAM bottles’ anti-colic features, you’ll notice they’re specifically designed to reduce the amount of air being swallowed when your baby feeds. These bottles come with venting systems and parts to help reduce airflow in the bottle during feeding. 

Bottle liners can serve the same purpose for reducing gassiness in fussy babies by contracting during feeding and limiting air contact with the milk. 


Baby bottle liners are convenient while helping to reduce unpleasant symptoms associated with colic or gas when your little one is being bottle-fed. Bottle liners can be used as a time-saver when washing bottles or a pediatrician may recommend them for colicky babies. They’re ideal for those days you’re away from home and have no access to washing facilities. 

When deciding how many baby bottles and nipples are needed, consider adding some liners to the list for those days when you want to save on cleaning time! This way, both you and your fussy baby will get all the benefits of using this alternative to an anti-colic bottle.

Last update on 2024-05-03 / Affiliate links / Images from Amazon Product Advertising API

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I’m Balint, founder of this site and a father (and dad) to a baby-turned toddler. I found the world of babies so fascinating that I started a blog dedicated only to that topic. By the way, I studied physics, engineering (PhD, MSc), and therefore I do a thorough research when I write about something. Since it’s a blog, of course I also write about my personal experiences.

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