When To Use Fast Flow Nipples – Is It Time To Move Up?

Hi there, dear parent,

When should you up the size of the nipple of the feeding bottle depends on 2 things- bottle-fed babies after 6 months can start using fast flow nipples while breastfed babies should maintain the same slow flow nipple as the milk flow from breasts are usually slow too.

You have so many options when it comes to which formula is best for your baby, or which feeding bottle is good for newborns, or the best anti-colic bottles for colicky babies, or whether you want a slow flow or a fast flow nipple for your baby.

My point being, you get a lot of options, and you need to make an informed decision. Otherwise, if you introduce a fast flow nipple to a younger baby, the chances of choking, gagging, and coughing increase while feeding.

Nipple flow levels

Every baby is unique, and so are their demands and the rate at which they drink milk.

Dr. Brown's Original Nipple, Level 2 (3m+), 6 Count

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Even though every brand is slightly different, and you might find different wording on each package, they all have a range available for different flow rates.

Level 0 (Preemie or extra slow flow)

These are best for premature babies or babies who have an immature digestive system.

Level 1 (slow flow)

This is typically for 0-3 months bottle-fed babies and breastfeeding babies as well. After that, they can switch between breastfeeding and bottle feeding.

Level 2 (medium flow)

This is for bottle-fed babies 3-6 months of age and can usually handle a medium flow nipple.

Breastfed babies at this age are still recommended to use the slow flow nipple unless the mother has a faster flow.

Level 3/4 (fast flow)

For babies above 6 months to 1-year-old bottle-fed babies are recommended fast flow nipples.

At this age, they’ve already started solids, and their sucking reflex has also developed, so they might usually prefer milk to come out of the bottle at a faster pace.

When is it time for a nipple size up?

When should you switch to a fast flow nipple?

1. Nipple size for bottle-fed babies

Typically for bottle-fed babies, 6 months is the recommended age when you can switch the current nipple with a fast flow one, but if the baby is satisfied with the current nipple, you don’t have to switch it up unless she starts getting fussy at the bottle.

If your baby keeps showing most of the above signs during feeding, then it’s time to switch the nipple size. A good rule of thumb is babies generally take 3 to 5 minutes to drink 1 ounce of milk.

So, if your baby takes 30 minutes or so to finish a bottle or keeps drinking for a long time and still doesn’t finish the bottle, then you should probably try sizing up the nipple.

On the other hand, if your little one chugs down the whole bottle within 5 minutes, then don’t hesitate to pull back and re-change the sizes and go back to medium flow nipple.

Remember that the size you’re using in the current brand wouldn’t be similar to another brand. So, always read labels and don’t necessarily depend on the baby’s age to change the nipple size.

If your 7-month-old baby is satisfied with the medium flow, you don’t have to change it because the brand packaging says that medium flow is for 3 to 6 months old babies.

2. Nipple size for breastfed babies

Doctors usually recommend a slow flow nipple for breastfed babies or even an extra slow flow nipple when they’re a newborn as the milk flow from the breasts is usually slow.

So, while switching from bottle to breast, a baby may not accept the breast because she keeps losing her patience while waiting for the milk to flow faster.

The cons of giving a medium flow nipple to a breastfeeding baby are, they might get lazy around the boob, tug harder for the milk to come faster, or even completely reject the breasts.

But, if you have a good milk supply and your flow is faster too, then you can try alternating between medium flow and slow flow and see how your baby reacts and adjusts to both the bottle and your breasts.

Before changing the nipple size, you need to first assess your milk flow and change accordingly.

You shouldn’t worry if your 10-month-old baby still drinks from a slow flow nipple because this probably means that she’ll be happy with flow from both the bottle and the breasts.

Also, while bottle feeding your baby– be it exclusively bottle-feeding or alternating with breastfeeding, always try pace feeding your baby and instruct the baby’s caregiver to do the same.


How do you know if a teat is too fast for your baby?

Signs like gulping harder, choking, purposely letting milk dribble out of the mouth, pulling away from the nipple, and breathing heavier will happen if the flow of the milk is too fast for the baby.

How often should I replace nipples?

As a general rule of thumb, replace nipples every 1-2 months of use, as they aren’t as durable as bottles. Also, if you see any discoloration, tear, or thinning, you should immediately change the nipples.

Can fast flow nipple make baby reflux worse?

Wrong nipple size or a fast flow nipple for a younger baby can make their reflux worse as they’ll be gulping large air bubbles along with the milk.


Finding the right nipple size is always a game of trial and error, and you know best which flow your baby likes. So, change the nipple accordingly.

Don’t worry if your baby doesn’t like fast-flow nipples because as long as they’re happy while feeding, satisfied, and actively playing, there’s nothing you have to worry about.

Happy feeding!

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Located in India and a mother to a joyfully mischievous son, Kelin is the wife of the world’s most patient man and a busy homemaker. When she’s not busy cooking and running after her kid,  you can find her in a corner reading, or penning down words on her laptop. She believes the world will always try to instil ‘mom guilt’ in new mothers, but she goes by the maxim ‘a mother knows best'.

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