Things to Know About Mixing Formula With Breast Milk

Some new mothers plan to breastfeed, while others determine from the get-go that the right option for them is a mix of breastfeeding and formula. There is no completely right answer here.

There are many reasons why moms might want to mix breast milk and formula such as if they discover their breast milk supply is low or their baby has difficulty suckling. Or maybe you’re going back to work and won’t have time to pump.

For some women, being able to both give breast milk and formula is simply just the best of both worlds. Up next, we’re going to tell you how to mix breast milk and formula correctly. 

Things to Know About Mixing Formula With Breast Milk
Image Source: The Conversation

When to Consider Combining

If you fail to generate enough milk to satisfy your cute yet insatiably hungry baby, you can naturally increase your supply by hydrating, eating well, and pumping regularly. 

However, sometimes despite your best efforts, you cannot meet the minimum milk requirements. Hormonal shifts may lead to supply problems as well as breast surgery, certain drugs, and even age.

A lack of milk supply can also affect moms of twins or multiples. Keeping up with the demands of multiple babies will leave you feeling exhausted and sucked dry. 

The answer you’re searching for could be combination feeding. 

What You Need to Know Before Considering 

Nipple confusion is sometimes overstated or even non-existent, most babies do fine going back and forth between breast and bottle. Some, however, may have a little difficulty. 

That’s why doctors usually recommend that you breastfeed exclusively for four to six weeks before the bottle and formula are introduced.

That might not be feasible depending on your situation, and even if you give them formula from the beginning, many babies will still not stop breastfeeding. 

The bottom line is that if you’ve agreed that both breastfeeding and formula are perfect for you, don’t worry about nipple uncertainty. 

The trick is to ensure that your baby loves both, and the best way to do that is to be consistent.

When you are mixing the two, make sure that during breastfeeding you switch between breasts and burp the baby between the sides. And during each feeding session, make sure to look into the eyes of your baby and give her plenty of cuddles.

How to Mix Formula and Breast Milk

Prepare Your Formula

You will first need to prepare it according to the instructions if you use powdered or concentrated formula, making sure to add the correct amount of distilled or clean drinking water. 

You should add your breast milk after you’ve combined the formula and water correctly. 

Notice that during formula prep, you can never use breast milk in place of water. Maintaining the proper water-to-formula ratio and then separately adding breast milk means that you will not modify the formula’s nutritional quality. 

Nutrients may be diluted by adding unnecessary water to formula, whereas adding insufficient water will place pressure on the kidneys and digestive tract of a baby, causing dehydration.

Safely Store Both Formula and Breastmilk 

For the preparation, use, and disposal of breast milk and formula, there are numerous laws. For 6 months, breast milk may be frozen in a food-grade plastic jar. It will remain in the refrigerator for 24 hours until it is thawed

Newly pumped breast milk can be saved for up to 5 days in the back of the refrigerator for up to 24 hours in an insulated cooler. 

An opened liquid formula container should be kept in the fridge and used within 48 hours. However, if you have pre-made bottles of formula, they should be used within 1 day. 

Similarly, it is important to use or discard a refrigerated bottle of formula mixed with breast milk within 24 hours.


If your finicky little love is used to your breast milk, they might turn up their teeny nose at the formula taste when you introduce it. But if you are mixing the two, they will more quickly get used to the taste of formula. 

It takes more time for the body of a baby to digest formula, so if you use both breast milk and formula together, they will be able to spend longer periods between feedings.

Things to Know About Mixing Formula With Breast Milk
Image Source: Today’s Parent


There’s no need for breast milk and formula to be mutually exclusive. Mix them, feed, and see what works for you and your baby. 

When preparing bottles, just remember to mix the formula as per directed before adding breast milk. We wish you luck, mommy!