When Do You Make the Switch to Size 2 Nipples?

If you’re wondering when to switch from size 1 nipples to size 2 nipples, you aren’t alone. Parents make the switch at different times depending on the brand’s recommendations. You should change the nipple size when your baby starts spending more time feeding and continues making progress in their feeding skills.


If you’re buying nipples for your baby’s bottles, you probably noticed that there are different options.

Naturally, the first size is 1. While size 1 is the right place to start, you will eventually need to switch to size 2.

You might be wondering how many nipples to buy and when to buy the next size up. If you are bottle-feeding, you might also be curious about different bottle and nipple brands.

How Long Should it Take Baby to Eat?

When you’re feeding your baby, you should expect it to take about 20 to 30 minutes for a full feeding.

If your baby is just “snacking,” it may take less time. If it seems to be taking your baby a long time to eat, it could be because the nipple flow is too slow, meaning that it’s time for an upgrade.

Bottle Nipple Sizes

Unfortunately, every bottle brand has its own nipples and sizes. Not having a standardized system makes it very difficult for parents to switch between brands.

Different Sizes for Different Brands

For example, let’s say you are using a Dr. Brown bottle. Dr. Brown’s recommends a Level 1 nipple for ages 0-3 months and a Level 2 nipple for ages 3-6 months. Other brands have different recommendations. It’s not as simple as all three-month-olds needing size 2 nipples.

With Avent bottles, the levels are different. Level 1 is the Newborn nipple, which is for babies that are 0+ months. Once babies are 1+ months, they can use the Avent Slow Flow nipple, level 2.

Nipples Made for Breast vs. Bottle Feedings

As you can see, not all brands follow the same system. Additionally, some brands have nipples that are specifically for breastfed babies.

Avent recommends using their Natural First Flow nipples to match the flow of breastfeeding.

Try A Few Brands Before Picking Your Favorite

When you are looking at bottles and bottle nipples, it’s essential to try to find one brand that works for you. You might buy a few different brands when you first start feeding your baby with the bottle.

There may be some trial and error to determine which option is best. To keep things simple, it helps to stick with the brand that works best for your baby. Then, you can progress from one level to the next with ease.

Signs That It’s Time to Switch Nipples

  1. Frustration: Your baby may be frustrated by the speed of the milk flow from their bottle. If your baby seems upset while eating, the milk may be coming out too slowly. They might get fussy or pull away while eating.
  2. Longer Feedings: Your baby is taking longer than 20 to 30 minutes to finish a bottle. This is a sign that the flow is too slow.

In these cases, your baby will need a faster flowing nipple. The next size up should work to make mealtimes more enjoyable for you and your baby.

Dr. Brown’s offers evidence-based information on nipple flow rates so you can understand how slow flow nipples came to be.

What Happens if You Switch Nipple Sizes Too Soon?

Remember that all babies are different. Your baby might show signs that it’s time to switch to another nipple, but it might be too soon.

If your baby cannot swallow the milk fast enough, that’s a sign that you should try a slow-flow nipple. Your baby might need to go back to the previous size, which would have a slower flow.

You can also buy nipples specifically labeled as slow flow, which can help if your baby is having trouble swallowing the milk fast enough.

Why is it Important to Switch Nipples?

It’s important to switch nipples to ensure your baby uses the right one for their specific needs.

As your baby gets older, they will develop better eating skills and use bottles that allow them to use those skills. They will be able to swallow milk more quickly and will want to eat more at once.

As mentioned, your baby might get frustrated if the milk is coming out of the bottle too slowly. Your baby might need a faster flow nipple to get the milk at the proper speed, especially when they start drinking larger amounts of milk.

Additionally, you might need to switch nipples over time as they show wear.

Switching Nipples Due to Damage and Wear

You might replace your baby’s bottle nipples due to wear and tear over time too. Bottles get a lot of use, and at some point, it may start to show.

You use bottles for your baby multiple times per day, wash them regularly, take them on the go, and more. Needing to switch nipples due to damage is inevitable. They will begin to show signs of wear.

If you see tiny teeth marks on the nipples, that can be a sign it’s time to switch them out. You might notice discoloration or changes in the shape of the nipple. Some nipples may start to fall apart and lose pieces.

Overuse Can Affect Nipple Flow

In some cases, the flow can be affected over time. You may not notice this regularly, so it’s important to test the nipples.

You can fill two bottles with water. One nipple should be new, and one should be older. Compare the flow of the two nipples.

If the older one doesn’t seem to flow like the new one does, it’s time to replace the old nipples.

When to Stop Using Preemie Nipples

If your baby is a preemie, you likely bought a preemie nipple. Preemie nipples have a slow flow so your baby can learn how to eat correctly. Look for the signs mentioned above to determine whether your baby is ready for a level 1 nipple.

As mentioned, if your baby doesn’t respond well to a level 1 nipple, it’s okay to go back and use the preemie nipples again.

It can take your baby some time to get used to the new nipple size, but you don’t want your baby to be missing out on calories and nutrients.

When to Switch Bottle Sizes

Most brands offer nipples that can be used interchangeably on any size bottle. At some point, your baby will need to use a bigger bottle to get a full meal as their appetite increases.

When you’re first buying bottles, you can choose to purchase large bottles, small bottles, or both.

Purchasing larger bottles to start may be helpful, as you will need them eventually. When your baby isn’t drinking an entire bottle, you can fill it halfway.

Some parents think that the smaller bottles are more convenient, so you might choose to get both.

Most parents buy 8-ounce bottles when their baby is around four months old. This age is when babies’ appetites start picking up.

If your baby is eating more, it can be more practical to use a larger bottle instead of using multiple smaller bottles.

Be Aware of Signs That Your Baby Is Ready to Switch Nipple Size

Ultimately, there’s no right or wrong time to change nipple sizes. There’s not a single answer that works for all babies. You know your baby best.

Pay attention to the signs that your baby might be ready to switch to a different nipple size. You can use the guidelines set by each bottle brand, but keep in mind that all babies are different.

They have individual needs and make progress at different rates. Your baby might need a size 2 nipple earlier or later than expected, and that’s okay.

If you have specific questions or concerns about feeding your baby, be sure to talk to your baby’s pediatrician or other medical professionals.