Combining Breastmilk and Formula Made Easy

baby combo-feeding formula newborn Nov 01, 2022
Mom feeds young baby a bottle of breastmilk and formula while baby looks up at mom and mom looks down at baby.

Many moms have an idea about how they would like to feed their babies.

Some may want to do 100% breastmilk. Others may want to use 100% formula.

Did you know it doesn’t have to be exclusively one or the other?

There are great options for using a combined approach for whatever reason you may have. Combination feeding can take a bit of work depending on individual circumstances and the quantity of milk produced, but it is feasible, I promise!


What is combo-feeding?

Combination feeding (AKA combo-feeding AKA supplementing with formula AKA top-offs) refers to any method of feeding a baby both breastmilk and formula. 

Using some formula and some breastmilk is actually a very common way to feed your baby, yet we are not often taught that this is a valid option.

 >>>  Do you want to be a confident combination-feeding mom while protecting your milk supply?  The Simple Guide to Combination Feeding is the answer to ALL your feeding questions from birth to your baby's first birthday.  <<<


Pros and cons of mixing breastmilk and formula

There are many different factors that play into combo feeding. Let’s take a quick look at some of the positive and not-so-positive outcomes.


  1. Combo feeding helps babies be fed enough to thrive. If a breastfed baby isn’t getting enough milk from the mother, supplementing can help.
  2. Combo feeding can help ease anxiety because you know how much your baby is taking in.
  3. Combo feeding lets your partner help! This is a great way for your partner to bond with the baby as well as share some of the load of caring for your baby.
  4. As a result of the partner taking on some of the feeds, this gives mama a well-deserved break.
  5. Combo feeding can also extend the amount of time breastfeeding can occur. 


  1. Combo feeding is more work. A baby that is exclusively breastfed doesn’t need bottles or formula and the time it takes to sterilize the bottles and mix the formula.
  2. Combo feeding may lower milk supply. Since breastfeeding typically works on a supply and demand basis, if the breast is not emptied as frequently, milk supply may dip.
  3. Combo feedings can lead to breast conditions such as blocked ducts, engorgement or mastitis. This is often caused by the breast not being emptied as frequently.
  4. Your baby may start to prefer either the bottle or the breast. Some infants will prefer the bottle over the breast once they are exposed to it and vice versa. It’s okay - there are ways to handle this!


How to combine formula and breastmilk

There are three common ways to incorporate combo feeding into your routine.

  1. You can breastfeed first, then follow up with formula. I always recommend following up with either expressed breastmilk or formula if your baby still seems hungry after a feed.
  2. You can also breastfeed most of the time, but select a feed a day to use formula.
  3. You could also pump on a schedule and offer baby a bottle of breastmilk mixed with formula.  
  4. You can do any combination of the methods above.

>>> If you want personalized recommendations for your baby, schedule a one-on-one virtual consult to find the best option for you and your baby. <<<


How to protect your milk supply while offering formula

Using only small amounts of formula and frequent milk removal are the best ways to protect your milk supply, 

Remember that milk supply is built on a supply and demand system. If you create less demand, there will be less supply.

Pumping when your baby is fed a bottle will help trigger your body to continue making milk to meet the demand.

If your baby is less than three months old, it is recommended to remove milk from the breast 6-10 times per day, even more frequently the younger the baby is. I recommend milk removal 8+ times per day until your milk supply regulates around 6-12 months.

For a baby older than 3 months, removing milk 5-6+ times a day at regular intervals is recommended.


Mixing formula and breastmilk

A question I am often asked is whether it is safe to mix breastmilk with formula. The answer is YES! You can definitely do this as an option for combo feeding.

First, you would mix the formula and then add the breast milk to the bottle, making sure the breast milk is the same temperature as the prepared formula.

There are no studies that suggest combining them will decrease the nutrient profile, so go ahead and combine the two if you'd like. Just remember to follow proper formula storage guidelines.


In short, combo feeding is a great way to feed your baby! Breastfeeding can still happen and YOU don’t have to shoulder the whole load.


>>> Do you want to be a confident combination-feeding mom while protecting your milk supply?  The Simple Guide to Combination Feeding is the answer to ALL your feeding questions from birth to your baby's first birthday. <<<


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