How do I Supplement my Breastfed Baby with Formula?

TheresaMA, RD

Read time: 6 minutes

What should I know about supplementing with formula?

  • How to supplement your breastfed baby with formula

  • How to maintain or increase milk supply while supplementing with formula

  • How to supplement with pumped breastmilk

Supplementing with formula is a very personal decision. Whether stemming from a medical need to supplement or simply choosing to, it’s important to do what works best for you and your family.

If you do supplement, know that this does not need to be the end of your breastfeeding journey. Should your goal be to continue breastfeeding, there are strategies that can help protect and even increase your milk supply.

What are reasons to supplement with formula?

There are many reasons someone may choose to supplement with formula, including:

  • Being away from baby, such as at work or school

  • Mom must take a medication that will cross into the milk and isn’t safe for baby1

  • Mom has a delayed milk production or a low milk supply2,3,4,5

  • Mom has had a prior breast surgery resulting in poor milk production6

  • Mom has intolerable pain during feedings7,8,9

How to supplement with formula

There are a couple of ways supplementation with formula can work for you and your baby.

Supplementing while you are away from baby. Some women choose to provide formula to their little one while they are out and about, or while at work. When supplementing like this, providing your little one with a full feed of formula to replace a breastfeeding session is the goal.

Occasionally providing formula while you are away will usually not affect your breastmilk supply. However, if you are providing formula on a regular basis, such as if you are working or at school, then your supply will drop unless you are also pumping.

Supplementing due to low milk supply. Some women may not be producing enough breastmilk and may need to supplement with formula for baby to get enough nutrition. When supplementing for this reason, it’s important to breastfeed first and then provide supplemental formula after.

This way you are emptying the breast as much as possible to help support your supply.

Read more: Introducing Formula to a Breastfed Baby

How is breastmilk supply regulated?

To understand how to maintain or even increase milk supply while supplementing with formula, it’s important to know how our body makes milk.

When it comes to milk supply, what’s most important is how often you pump or feed, and if the breasts are being fully emptied.10 The more milk that is taken out of the breast, the more milk the body will make.11,12

Should you like to continue breastfeeding while you supplement with formula, you may need to pump regularly. This will tell your body to keep up your milk supply.11

Learn more:

How to Choose the Right Breast Pump

Top Tips for Pumping Breastmilk

How to maintain breastmilk supply while supplementing formula

If you are giving formula during a time that you would normally be breastfeeding, such as while you are at work, pumping will help maintain your breastmilk supply.13 The goal is to pump as many times as your baby takes a bottle.14,15 If you do not pump, the body will think baby no longer needs that milk and your supply will decrease over time.

Should you end up pumping full bottles of breastmilk, you can store these to use next time you are away. For example, if you are working, refrigerate the bottles to provide freshly pumped breastmilk to your baby the next day.

Not all women enjoy pumping or are even able to pump while away. It’s okay to simply provide formula while you are out of the house and allow your supply to adjust down; making milk only for the times when you consistently breastfeed. It is important to do what works best for you!

Read more: Safe Storage of Pumped Breast Milk

How to increase breastmilk supply so you can stop supplementing with formula

If you are supplementing with formula because your breastmilk supply is low, your goal may be to increase your supply and eventually stop providing formula. To do this, consider pumping after each time baby breastfeeds.16

Your goal would be to first breastfeed, then provide supplemental formula if needed, then pump. Other strategies include: pumping between feeding sessions rather than directly after one, or breastfeeding on one side while pumping the other side.15,17,18

This can be quite an intensive process for a mom of a newborn. While some moms may find this schedule worthwhile, you may reevaluate your feeding goals over time.

Read more: Dealing with a Low Breastmilk Supply

Tips for pumping to increase supply

You may not get much breastmilk when pumping directly after your baby feeds. This is because baby is taking most of the milk during their feed. The goal of this pumping session is to help fully empty the breast after each feeding to help stimulate the body to make more milk.19

Quick tips for pumping to help increase supply

  • Be consistent and pump every day

  • Always pump at the same time of day

  • Pump both breasts at the same time

  • Hand massage the breast while you pump (as well as while breastfeeding) to help empty the breast.

  • Pumping should not hurt. If it does, make sure the suction is not too high and that the flange is fitting correctly.12,17,19

Remember that increasing supply may take anywhere from a few days to a few weeks depending on the mother and her situation. Continue to be consistent about pumping at the same times every day to help the body respond.12

If you want to learn more about increasing your milk supply, reach out to our team of registered dietitians and lactation consultants for free! They’re here to help on our free live chat from Mon-Fri 8am-6pm (ET), and Sat-Sun 8am-2pm (ET). Chat Now!

Tips for supplementing with formula and breastmilk

First: Know that it’s okay to combination feed!

If the goal is not to eventually exclusively breastfeed, or if mom plans to wean to formula, simply breastfeeding then providing formula may be a great strategy. Know that any amount of breastmilk is beneficial for your little one.18

Your pediatrician and/or lactation consultant can help guide you as to how much and how often you should be giving your baby a bottle of supplemental formula.

Learn about: How Much Formula Does My Baby Need?

Use Paced Bottle Feeding

If your goal is to continue breastfeeding or even to eventually stop supplementing, paced bottle feeding can help.

Babies latch differently at the bottle than they do the breast, which may cause a shallow more painful latch when breastfeeding.20 It is also easier for babies to get milk from the bottle compared to the breast, sometimes creating a frustrated baby when trying to breastfeed.21

Paced bottle feeding slows down a bottle feeding to be a similar speed as breastfeeding and helps put baby in control.20,22 This may help to reduce any preference that may develop for the bottle.

For detailed steps on how to do Paced Bottle Feeding, read this article: What is Paced Bottle Feeding?

Hand massage or express before latching baby to breastfeed

Before putting baby to the breast, hand express or massage the breast until you feel milk is about to come out (this is your ‘let-down’ reflex). This way breastmilk is ready to go, just like with a bottle, when baby latches. This can help reduce frustration.

Read more: How and When to Hand Express Breast Milk

Every infant feeding journey is different

While making the decision to supplement with formula is not taken lightly, you must do what is best for you and your baby. While breastfeeding in any amount will provide benefits for your little one, if it is causing anxiety and stress for you or your baby, then it may be doing more harm than good.

Reach out to a lactation consultant for an in-person assessment. They will be able to observe baby’s latch and asses your milk supply to give you individualized support.

Learn about: Could this be Postpartum Depression?

Let's Chat!

We know parenting often means sleepless nights, stressful days, and countless questions and confusion, and we want to support you in your feeding journey and beyond.

Our Happy Baby Experts are a team of lactation consultants and registered dietitian nutritionists certified in infant and maternal nutrition – and they’re all moms, too! They’re here to offer personalized support on our free, one-on-one, live chat platform Monday - Friday 8am-6pm (ET), and Saturday - Sunday 8am-2pm (ET). No appointment needed, no email or sign-up required. Chat Now!

Read more about the experts that help write our content!

For more on this topic check out the following articles:

Dealing with a Low Breastmilk Supply

Breastfeeding: Supporting a Good Milk Supply

Formula Preparation: What Type of Water Should I Use?

Everything You Need to Know About How to Prepare and Store Formula