Supplementing With Formula & Breastfeeding

supplementing with formula

Supplementing Breastfeeding With Formula

Maybe you were told that supplementing with formula is medically necessary. 

Perhaps you are wondering if it would make your life a bit easier to supplement with formula along with breastfeeding. 

Or you could be worried that your baby isn’t getting enough from breastfeeding alone! 

We’ll talk about all these things, and ultimately the choice is up to you, mommy. But if you aren’t sure or are looking for answers, it might help to see a lactation consultant to determine if it’s something that will help your situation.

supplementing with formula and breastfeeding

Breastfeeding And Supplementing With Formula

It’s usually not necessary to supplement with formula, especially with a healthy, full-term baby. Often a mom will wonder if her supply is adequate because newborn babies can be fussy, sleep a lot and eat constantly. 

If supply issues are the concern, generally supplementing isn’t necessary!

But what happens goes something like this: 

A baby is fussy, eating constantly and mom starts to worry that her baby is hungry. She begins to think that breastfeeding isn’t enough, so she offers her baby a bottle of formula. 

Her baby sucks it down quickly and then falls into a deep sleep. Then her baby isn’t hungry again for a while (when breastfeeding was almost constant). 

Mom comes to the conclusion that she needs to supplement. As a result, her baby doesn’t nurse as frequently and her supply drops until supplementing does become necessary… and then breastfeeding stops altogether because her supply dwindles or disappears. 

Generally starting formula wasn’t necessary in the first place! Breastfed babies eat frequently because breast milk is easier for them to digest. Also, using a bottle encourages a baby to suck down a huge feeding quickly. A bottle flows entirely differently from a breast. 

So while the baby seemed hungry when sucking the formula down, they were just gulping because the formula flowed so quickly into their mouth. 

Baby didn’t eat for a long time after… because formula is harder to digest than breast milk. Because baby wasn’t nursing, his mom’s body got the message that it didn’t need to make as much milk and then her supply dropped. 

It’s a vicious cycle. 

So, before just trying it….

Make sure your baby is getting enough milk! If they are pooping 3-4 times a day by 4 days of life and gaining weight consistently, they are eating enough and don’t need a supplement. At around 6 weeks of life some babies only poop once per day or less, but if they keep gaining weight they are fine!

Newborn babes can be fussy and feed constantly. But that’s not a bad thing! It helps promote bonding and builds a good milk supply for the rest of your time breastfeeding. 

Did you know that moms who are started on supplementing in the hospital are more likely to stop breastfeeding completely? 

And moms that stick with breastfeeding (even if the first few weeks are difficult), the VAST majority will breastfeed successfully! The newborn phase isn’t always easy but with time and persistence breastfeeding becomes second nature.

Formula Supplementing With Newborn

Let’s talk about formula supplementing with a newborn. 

Know that generally, supplementing a newborn isn’t necessary. Colostrum is what your breasts produce in the first days after birth before your milk comes in. 

It’s a small amount of liquid, but it’s packed full of nutrients. Additionally, your baby’s stomach isn’t very big. It’s enough for your baby to just have colostrum. 

Newborn babies are expected to lose weight. 

They have extracellular fluid throughout their body because they were immersed in amniotic fluid. 5-7% weight loss is expected, and even up to 10% weight loss can be normal (depending on circumstances like IV fluids during labor). 

So, just because your baby loses weight doesn’t mean anything is wrong. 

Your milk should come in between days 2 and 5… that’s when weight gain will start to pick back up and your baby should be back to normal weight by 2 weeks. As long as that happens, and they are having 3-4 dirty diapers per day then supplementing isn’t necessary. 

The following are NOT signs that supplementing is necessary: 

  • A sleepy baby. Newborn babies sleep a lot! They might wake every 20 minutes to feed for 5 minutes or they might sleep for 3 straight hours! Wake your baby to feed if they haven’t eaten for the past 3 hours. But sleepiness isn’t a sign of needing supplementation. 
  • Baby loses weight after birth. This is expected! 5-7% is normal for most babies but if mom received an IV during labor, her baby can lose up to 10% of their birth weight and still be normal. 
  • Constantly breastfeeding baby. Some babies want to do nothing all day but take catnaps and eat. Especially in the newborn phase! This is normal, babies have different eating habits. Frequent feeding also helps a mom establish her supply. With time the frequency of feedings will decrease as your baby’s stomach grows. 
  • A fussy or unhappy baby. The average amount of time a newborn baby cries per day is 2-2.5 hours! That’s average which means some babies cry more! Fussiness and crying is just something babies do… some more than others. It isn’t necessarily a sign of hunger.
  • A tired mommy. I know postpartum can be exhausting. But supplementing might not help with that! If you want to keep your milk supply up, you’ll have to pump each time you supplement your baby. That just transfers the effort from breastfeeding to pumping, storing milk and dealing with a bottle. Weigh your options before supplementing! 

If you’re worried about your baby eating enough, just pay careful attention to their hunger cues. They may be frequent but catching your baby’s hunger cues and feeding them on demand will help with fussiness, milk supply and feeding enough!

So what should you do instead of supplement? 

  • Learn how to breastfeed. It can be so overwhelming starting a breastfeeding journey! And each baby is different so the second one can sometimes be harder than the first. Knowledge is power so try to brush up on what to expect and how to breastfeed. 
  • Get a good latch. A good breastfeeding latch is essential for proper milk transfer. If your baby is latched on deeply, they will be more efficient at feeding and you shouldn’t need to supplement with formula. 
  • Don’t worry! Moms worry about so much these days. Take a deep breath and know that babies aren’t textbook. They are all their own little people, with personalities and hunger patterns. Babies cry, and mommies worry about every little thing. Try and recognize your babies successes (like poopy diapers and weight gain) and don’t worry about adding more stressors to the mix. 

Keep reading for more information about supplementing with formula… and some medical reasons why it might actually be necessary! 

formula supplementing with newborn

Reasons To Supplement With Formula

Supplementing with formula while breastfeeding isn’t necessary for the vast majority of moms. It can introduce unforeseen problems, and should be avoided if possible. 

But there are some rare cases when supplementing with formula is necessary. 

You might need to supplement if: 

  • Your baby loses more than 10% of their birth weight.
  • There’s no milk coming in by day 5.
  • Your baby doesn’t poop 3+ times per day after day 4 of life.
  • Your baby still has meconium poops on day 5 (the black, tarry kind).
  • You have glandular insufficiency, didn’t notice breast changes during or after pregnancy or have a very low milk supply coming in.
  • Previous breast surgery or trauma.
  • Excruciating, unbearable pain while breastfeeding that isn’t resolved with help and techniques. 
  • You start a temporary medication that isn’t safe for your baby while breastfeeding. 

These instances are rare, but are reasons to supplement with formula. In many cases, time will help and breastfeeding can be started back up again. 

But sometimes, formula will need to be supplemented long term. 

Know that any breast milk you give your baby is wonderful! 

And formula is the next best thing for your baby after breast milk. 

Temporarily Supplementing With Formula

If you have a situation that requires temporarily supplementing with formula, be careful about how you proceed if you want to continue breastfeeding. 

You might need to temporarily supplement your baby if you start a short-term medication that’s incompatible with breastfeeding. Or perhaps you and your baby will be separated for a time. 

The best option for the breastfeeding relationship is to use a cup or syringe to feed your baby. A cup allows your baby to use the same mouth muscles as when they breastfeed. 

A bottle might create nipple confusion for your baby so if supplementing is temporary, consider learning how to feed with a cup. 

Of course it’s not always possible, so just do the best you can. 

One thing that you need to do if you intend on returning to breastfeeding is keep your supply up! That means you need to pump as much as if your baby was breastfeeding. So if your baby is less than 6 weeks old – that’s every 2-3 hours! 

Your breasts need stimulation in order for you to keep up enough of a milk supply to return to breastfeeding. 

reasons to supplement with formula

Does Supplementing With Formula Reduce The Benefits Of Breastfeeding?

If you can give your baby any amount of breast milk, you are doing a wonderful thing! Breast milk has so many benefits even if your baby only gets a little.

However, adding formula to your baby’s diet actually does change their digestive system slightly. 

Also, supplementing with formula usually leads to moms stopping breastfeeding altogether. 

It’s a slippery slope which is why most healthcare advice is against it (as long as your baby is meeting other milestones). 

If your baby needs it though, don’t be afraid to give it! Formula is the next best thing to breast milk and babies need to be fed. 

And if you make the choice to transition to formula, know that you aren’t alone. Many moms formula feed and they have happy, healthy babies. 

Is it okay to breastfeed and use formula?

Yes, it’s okay to breastfeed and use formula! But first try and think about what you want out of your feeding relationship with your baby. 

Everybody is different. If you want to breastfeed long term, using formula can inhibit that. 

If you want someone else to enjoy feeding the baby, an occasional formula bottle might be a good option! 

Just remember that if you want to continue breastfeeding, you need to keep your milk supply up. Any amount of formula your baby eats should be pumped so your body continues to produce milk. 

Maybe a good option for you would be to pump some milk and use a bottle- that way you are still expressing milk but you have the freedom of a bottle if you choose. 

Supplementing With Formula At Night

It’s possible to give your baby formula at night and breastfeed during the day. 

You should probably wait 4-6 weeks though until your milk supply is established. 

If you introduce a bottle at night, sometimes it helps for someone else to give the bottle. Babies smell their mother’s milk so may be confused when a bottle is offered instead of a breast. 

You will want to start this process gradually. Replace one feeding at night, then wait a few days to replace another. Doing it gradually prevents mastitis or other problems. 

If you decide to supplement with formula at night but want to breastfeed during the day, you will need to pump. Pumping during the night helps your milk supply stay up and prevents engorgement or mastitis. 

If you transition gradually, you might only need to pump once at night – just pay attention to your breasts and when they become over-full. If they get too full, your supply during the day might be affected. 

Honestly, I think that pumping during the night is more of a headache than just breastfeeding! There are some breastfeeding positions that allow your baby to feed while you lay down which might be helpful. 

As your baby gets older, they should naturally start having longer stretches of sleep at night where they won’t need to be fed at all. 

How To Start Supplementing With Formula

When you start supplementing with formula, the best way to give it to your baby is with a cup. 

Supplemental nursing systems are also an option, but they can be expensive, tedious to use and difficult to clean. 

Some women find them very useful though so if you think it might help, go for it! 

Supplemental nursing systems allow your baby to supplement while they breastfeed by attaching a small tube (connected to a bottle or formula) to your breast. 

Another option is using a syringe, especially if your baby is a newborn. 

Most often bottles are used, which makes sense! They are easy to use and familiar. The problem with bottles is that babies eat from them differently than breastfeeding. 

Different muscles in the face work when eating from a bottle, but cup feeding actually uses the same muscles as breastfeeding. 

Another challenge with bottles is nipple confusion. Some babies start to prefer the bottle instead of breastfeeding. To avoid confusion, use a wide-base nipple with slow flow. 

Also use paced feedings by holding the bottle horizontal (just so there’s milk in the nipple); preventing gravity from doing all the work. 

The goal is to make bottle feeding as close to breastfeeding as possible, so you will be able to continue breastfeeding successfully. 

Supplementing With Formula Without Decreasing Milk Supply

The biggest concern with supplementing is how it can affect your milk supply! 

Supplementing with formula is generally a slippery slope that results in reduced milk supply and decreased breastfeeding. The common result is for breastfeeding to cease all together. 

So how do you make sure to keep your milk supply up? 

Pump as much as baby eats! 

Did your baby eat 3 ounces of formula? Then pump 3 ounces of milk. 

Know this though… a breast pump is not as effective as a nursing baby. 

So, if you don’t pump enough milk then leave the pump on for at least 5 minutes after the flow of milk stops. A good rule of thumb is that each pumping session should last at least 20 minutes. 

If your baby is a newborn, you need to express milk as often as your baby feeds. So if your baby breastfeeds for a feeding that’s great! But if the next two feedings are formula, you need to express milk both times. 

Breast milk supply is dependent on demand. The more your baby breastfeeds (or the more you pump), the more milk your body will make. Pumping is important when supplementing with formula because it naturally helps tell your body to keep up with production. 

If you are separated from your baby after birth or start formula immediately, pump or breastfeed as soon as possible. Your body needs the message that it’s time to start making milk! So either breastfeed your baby or start pumping as soon as possible after delivery. 

Generally you should start breastfeeding (or pumping) within an hour of birth. That’s not always the case though, so try and do it at least in the first 24 hours. 

Best Formula For Supplementing

If you need to supplement, the best thing you can give your baby is your own milk. 

Sometimes a newborn baby has difficulty breastfeeding but is able to use a bottle (with a tongue tie for example). In a case like this, the best thing to do is pump and then give your baby breast milk. 

Not only is breast milk the best thing to give your baby, but pumping will ensure your milk supply is established well. Then you’ll have enough of a supply to return to exclusive breastfeeding. 

However if you need to use formula, it’s best to use an iron-fortified, milk-based formula. 

Each baby responds to formulas differently though. 

For example, my daughter is severely allergic to cow’s milk so she had to use soy. 

Some formulas might cause a baby to have more reflux or have stomach problems. It might take a little trial and error to find the one that’s best for your baby. 

Formulas come in all different versions. There are sensitive formulas, soy formulas, and even hydrolyzed formulas for babies with allergies. 

Just try small samples at first until you determine how your baby handles that specific brand or type. Once you find a formula your baby does well with, stick to it!

Combining Breast Milk and Formula

It is possible to breastfeed and to supplement with formula. 

But some moms wonder if they should or could mix their breast milk with formula. 

It’s not recommended because if your baby doesn’t drink all of it, you will waste your breast milk. Since breast milk is better for your baby’s health and digestion, feed them all the breast milk you have first. Then give your baby formula afterwards if they need more. 

Additionally, never add formula powder to your breastmilk in order to increase calories. 

Your baby needs the right combination of calories and liquid for their health and hydration. If they become full without getting enough liquid, severe health problems may result. 

Electrolyte imbalances and dehydration can lead to cellular problems. 

Formula is thoroughly researched and made perfectly for your baby. It has the right ratio of powder to water, so make it as directed to keep your baby safe. 

Weaning Off Formula To Breastfeeding

Here is how to wean off of supplementing with formula and get back to breastfeeding. 

First… breastfeed frequently! You should aim at breastfeeding at least 10 times per day to encourage your milk supply and get back to breastfeeding. 

Then follow these steps: 

  1. Measure the amount of supplement you give your baby each day. 
  2. Slowly decrease the amount of supplement by 1 ounce every couple of days. It is a gradual process. 
  3. If your baby is used to being finished with a bottle, put expressed milk into the bottle instead of formula. In addition, start pumping more often to build your milk supply. 
  4. Once you are producing enough milk, start weaning off the bottle. 
  5. Whatever you do, DON’T reintroduce formula! If you are increasing your supply and your baby is eating enough from what you make, reintroducing formula can lead to a slippery slope of problems. 
  6. When building your supply, pump for at least 20 minutes per session each time your baby breastfeeds. Additionally, if you breastfeed your baby and then pump, leave the pump on for an additional 5 minutes after you stop seeing milk come out. 

Some babies start to prefer the bottle to breastfeeding. When weaning off formula to breastfeeding, try to make the bottle as close to breastfeeding as possible! Make times at the breast happy and give your baby lots of cuddles. 

If your baby cries when trying to breastfeed, don’t force it. Offer the bottle… but make it less rewarding with these steps. With time your baby will be back to breastfeeding. 

How to wean off a bottle if your baby prefers it to breastfeeding: 

Try to minic breastfeeding as much as possible – make the bottle less rewarding. 

  1. Use a wide-base bottle nipple with slow flow.
  2. Keep the bottle horizontal so gravity doesn’t help milk flow into your baby’s mouth. 
  3. Don’t just stick the bottle into your baby’s mouth, touch their lip and let them smell the milk. Wait for your baby to open their mouth on their own – then give them the bottle. You’re basically letting your baby latch and work for the milk. 
  4. Do paced feeding. When your baby takes a break from sucking, tilt the bottle back so there isn’t milk in the tip. You can also remove the bottle until your baby is ready to continue the feeding. 
  5. Try the bait and switch. If your baby is happily sucking on their bottle, you can take it out of their mouth and latch them onto your breast. Some babies will continue to happily suck and breastfeed. It doesn’t work for all babies, but it’s worth a try. 

When weaning off of supplementing, pay attention to your baby’s dirty diaper count and their weight gain. The most important thing is to feed your baby and make sure they’re getting enough calories! 

It will be helpful to let your pediatrician know that you plan on weaning so they can help you monitor your baby’s weight gain and health. 

Supplementing With Formula Conclusion

There are a lot of things to consider when supplementing with formula. Make sure that there is a good reason to start supplementing because it can cause problems with your milk supply and breastfeeding relationship. 

Supplementing with formula is common and many moms are successful with it! If you want to supplement with formula while breastfeeding or wean off of formula, support might be useful. There are mommy breastfeeding support groups and lactation consultants that can help you. 

I am always happy to talk with moms that have questions so visit my website for a consultation!

Kealy Hawk lactation consultant
Kealy Hawk, BSN, RN, CLC

Kealy is a Registered Nurse, Lactation Counselor, and most importantly a mommy! Her own baby feeding struggles gave her a passion to help moms throughout their feeding journey. She specializes in breastfeeding support and evidence-based formula recommendations. To talk with Kealy or take one of her breastfeeding or formula classes, visit

how to supplement with formula
supplement with formula at night
supplement with formula while breastfeeding

Leave a Comment

Your email address will not be published. Required fields are marked *