Did you know that combo feeding (using both breast milk and formula) is one of the most common ways babies are fed during their first year?

Many parents (and medical providers) assume feeding has to be one or the other: either exclusively breastfeeding or exclusively formula feeding.

In reality, many families end up doing some form of combination feeding at some point.

Maybe milk supply isn’t quite meeting baby’s needs. Maybe you’re returning to work. Maybe you simply want more flexibility.

Whatever the reason, combination feeding is a valid and healthy way to feed your baby.

When done thoughtfully, combo feeding can support your baby’s growth while allowing you to continue providing breast milk.

This guide will walk you through:

• How to combo feed

• How much formula to give

• Whether combo feeding is bad for babies

• How to protect milk supply

• The best formula to mix with breast milk

• Combo feeding schedules with pumping

• How to start combo feeding at 3 months or earlier

What is combo-feeding?

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

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

The truth is that combo-feeding depends on many factors. 

It can be difficult to figure out how to protect your milk supply while offering formula. 

Even then, mixed feeding is still a valid option that helps many babies grow and thrive.

>>>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.<<<

Is mixing breastmilk and formula bad?

Unfortunately, “Is combo feeding bad for my baby?” is a question that comes up a lot.

The answer is no.

Combination feeding is safe and healthy when done properly.

Both breast milk and formula are designed to support infant growth and development.

Breast milk provides

• Antibodies and immune support

• Digestive enzymes

• Hormones and growth factors

Infant formula provides

• Consistent nutrition

• Essential vitamins and minerals

• Reliable calories for growth

For many babies, combo feeding actually helps ensure they receive enough calories while still benefiting from breast milk.

The American Academy of Pediatrics (AAP) notes that infant formulas available in the U.S. meet strict nutritional requirements and support healthy infant development.

>>> FREE QUIZ: What formula is best for your baby? <<<

Pros and Cons of Combination Feeding

Like any feeding method, combo feeding has advantages and disadvantages.

Pros of Combo Feeding

1. Supports healthy weight gain

If a baby isn’t getting enough milk from breastfeeding alone, formula supplementation can help ensure they receive enough calories.

2. Reduces feeding stress

Some parents feel more confident knowing exactly how much milk their baby is receiving from bottles.

3. Allows partners to help

Bottle feeding allows partners or caregivers to participate in feeding and bonding with the baby.

4. Provides flexibility

Parents can leave the house, return to work, or get longer stretches of sleep.

5. May extend breastfeeding

Many parents continue breastfeeding longer when they remove the pressure of exclusively breastfeeding.

Cons of Combo Feeding

1. More feeding equipment

Bottles, formula, and pumping equipment add extra steps.

2. Milk supply may decrease

Breast milk production works on a supply-and-demand system. If milk is removed less frequently, supply may decrease.

3. Possible breast discomfort

Skipped feedings can lead to:

• Engorgement

• Blocked ducts

• Mastitis

4. Bottle preference

Some babies develop a preference for either the bottle or breast.

The good news is that most of these challenges can be managed with a thoughtful combo feeding plan.

How to Combo Feed a Baby

There is no single correct way to combo feed.

Families use a variety of approaches depending on milk supply, lifestyle, and baby’s feeding needs.

Here are three common methods:

1. Breastfeed first, then offer formula

This is one of the most common approaches.

Steps:

1. Breastfeed your baby.

2. Watch for hunger cues.

3. Offer a small bottle of formula if baby still seems hungry.

This method helps protect milk supply because your baby still stimulates the breast first.

2. Alternate breastfeeding and formula feeds

Some parents choose certain feeds to be formula feeds.

For example:

• Breastfeed in the morning and evening

• Formula during daytime feeds

This can work well for parents returning to work.

3. Pump and offer bottles of breastmilk and formula

Some families pump breast milk and combine it with formula in bottles.

This allows for a predictable feeding routine while still providing breast milk.

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 weeks.

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

Can you mix breastmilk and formula in the same bottle?

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

Many resources say that the only way to combine breast milk and formula is by offering a bottle of breast milk and then following up with a bottle of formula.

You can do it this way, but another option is mixing breast milk and formula in the same bottle.

It does come with a little risk, though. Your baby could refuse the bottle with formula in it, which may result in you needing to throw away precious breast milk. Alternatively, it may help some babies be more accepting of formula when it is combined.

Here is the best practice for combining breast milk and formula in the same bottle:

First, you would mix the formula as directed on the formula container. You then add the breast milk to the bottle, making sure the breast milk is the same temperature as the prepared formula to limit the growth of bacteria.

I have seen a rumor that combining breast milk and formula decreases the nutrition a baby receives from breast milk.

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.

What is the best formula for combination feeding?

Here is the great news: any formula found on the shelf at the grocery store has been proven to promote infant growth and development. 

Each baby formula recipe has been reviewed by the FDA and has undergone clinical trials. 

This means that there isn't necessarily a "best" baby formula.

The best baby formula is one that your baby tolerates and that you feel good about feeding them. 

It comes down to a matter of preference because no formula will promote more growth or development than any other formula.

>>> FREE QUIZ: What formula is best for your baby? <<<

Mixed Feeding Schedules

There is no right way to mix-feed your baby! There is a lot of variance based on age, milk supply, appetite, and weight gain needs. 

There are a few common ways families make mixed feeding work:

• You can breastfeed first, then follow up with formula. I always recommend following up with either expressed breast milk or formula if your baby still seems hungry after a feed.

• You can also breastfeed most of the time, but select a feed a day to use formula via a bottle.

• You could also pump on a schedule and offer baby a bottle of breast milk mixed with formula.

• You can do any combination of the methods above.

Triple feeding schedules for newborns

The early days of breastfeeding can be very challenging. 

I see many moms in clinic with feeding concerns. 

If your milk supply has not transitioned from colostrum to mature milk, it might be necessary to supplement with formula or donor milk.

What is triple feeding?

It means that each time your baby is hungry, you breastfeed first and immediately pump afterward while someone else (hopefully) gives your baby a bottle. This ensures your baby's caloric needs are met while your milk supply is not meeting your baby's demands. 

Baby gets more practice at the breast while pumping triggers the brain to make more milk.

Triple feeding is meant to be temporary, usually lasting less than 5 to 7 days. 

If you need to triple feed or supplement longer to meet your baby's demands, I recommend getting to the root cause of the issue with a visit with a lactation provider. I can also help via a virtual consult.

Combination feeding from birth

Some babies are combo fed from the very beginning.

Common reasons include:

• Medical conditions

• Low milk supply

• Blood sugar concerns

• Parental preference

Hospitals may recommend early supplementation for babies experiencing:

• Low blood sugar

• Excessive weight loss

• Dehydration

In these situations, combo feeding can support both infant health and breastfeeding goals.

How combo-feeding worked for my family

Both of my boys were fed breast milk and formula throughout their first year.

Max was born in January 2020, right before lockdown. There was such limited support at the time. 

I had an oversupply early in pregnancy. 

Max started sleeping 12 hours (inconsistently) at 12 weeks. 

Unfortunately, I could not maintain my milk supply even with pumping before bed. He did not gain weight between his 4 to 6-month visits. 

I would love to say I started formula right away, but instead, I loaded him up on solids, which made my milk supply decrease even more. 

By 7 months, I knew I needed to add in formula.

We combo-fed by directly breastfeeding in the morning. 

While I was at work during the day, I made bottles with pumped milk and formula. I then directly breastfed before his bedtime and did a dream feed.

Elliot was born in March 2023. Though I had controlled gestational diabetes, his blood sugar was 17. He got glucose gel, and I promptly asked for formula while they were busy stitching me up. 

He was combo-fed through 2 tongue tie revisions, numerous lactation visits, and feeding therapy.

He started refusing bottles around 3 months, which was so stressful when I needed to leave for extended periods. Read more about BOTTLE REFUSAL here <<<

From 5.5 months until he started drinking efficiently from a cup, he received breast milk and formula via purees while at school and was directly breastfed at home. He was mixed-fed until we weaned at one.

It was challenging to figure it out, but it was the best option for my family during both postpartum periods.

Does Combo Feeding Help Babies Sleep Longer?

Another common question parents ask is:

“Does combo feeding help babies sleep better?”

There is no strong evidence that formula alone improves infant sleep.

However, combo feeding may indirectly help some families because:

• Formula can provide predictable feeding volumes

• Parents can share nighttime feeds

• Babies may feel fuller after larger bottle feeds

That said, infant sleep is influenced by many factors beyond feeding.

FAQ: Combo Feeding Your Baby 

Can I combo feed a baby with a tongue tie or feeding difficulties?

Yes! Combo feeding can help babies with tongue ties, latching issues, or low muscle tone get enough calories while still practicing breastfeeding. For personalized guidance, please speak with your pediatric provider, a lactation consultant and feeding therapist to balance breast and bottle sessions safely.

We had to do this with Elliot. While it was a lot of work, it was absolutely necessary.

How do I know if my baby prefers the bottle over the breast?

Some babies may prefer the faster flow of a bottle. Signs include pulling off the breast, fussing, or falling asleep quickly while nursing. Try paced bottle feeding or offering the breast first to maintain breastfeeding alongside formula.

Make sure the bottle flow is not too fast. For newborns and young babies, each ounce in the bottle should take between 5-10 minutes.

Free quiz: how much should my baby eat?

Can I combo feed once my baby starts solids?

Absolutely. Combo feeding works alongside solids from around 6 months, with breast milk or formula still providing most of your baby’s nutrition. Gradually adjust amounts based on appetite and growth.

Does combo feeding cause more spit-ups or digestive issues?

Most babies tolerate combo feeding well, though some may experience mild spit-ups or gas while adjusting. Introduce formula slowly and monitor for intolerance. Consult your pediatric provider if digestive issues persist.

How do I safely store mixed breast milk and formula bottles?

If you mix breast milk and formula in one bottle, use immediately or store according to guidelines:

• Once feeding starts, finish within 2 hours

• Do not refreeze or reuse leftover milk
  For detailed prep and storage tips, see how to make formula feeding easier. <<<

Can combo feeding help with cluster feeds or growth spurts?

Yes! During growth spurts or cluster feeding periods, top off breastfeeds with formula to ensure your baby gets enough calories without disrupting breastfeeding.

How do I combo feed at daycare or while traveling?

Plan ahead by prepping bottles in advance or using ready-to-feed formula. Communicate your feeding plan with caregivers and label each bottle with the date, time, and contents to ensure safety.

Different daycares have different protocols for formula and bottle prep.

Does combo feeding affect long-term milk supply?

Milk supply can decrease if breast milk is removed less often. Maintain supply by pumping during bottle feeds. Most babies still benefit from breast milk even with partial supplementation.

Is there a “best formula” to use for combo feeding?

All standard infant formulas meet FDA nutritional requirements. There is no single “best” formula for combo feeding, though parents sometimes choose gentle, organic, or partially hydrolyzed formulas for babies with sensitivities.

>>> FREE QUIZ: What formula is right for your baby? <<<

Can combo feeding reduce feeding anxiety for parents?

Yes! Many parents feel more confident knowing their baby is getting enough nutrition. Combo feeding can reduce stress while allowing partners or caregivers to participate in feeding and bonding.

I was finally able to enjoy feeding my oldest when I wasn't focusing on how many sucks and swallows he was having. I know I am not alone.

Combo-feeding is an excellent way to feed your baby...you get assurance that your baby is getting important calories, and you are providing benefits from your breast milk. 

It can be daunting when trying to figure it out, so make sure to ask for help when it comes to mixed feeding. I am here when you need me!

Sources:

American Academy of Pediatrics. Infant Feeding Guidelines.
Centers for Disease Control and Prevention. Breastfeeding Data and Statistics.
Academy of Breastfeeding Medicine Protocol #3: Supplementary Feedings in the Healthy Term Breastfed Neonate.
World Health Organization. Infant and Young Child Feeding Guidelines.