Most expecting moms plan to breastfeed exclusively once their little one arrives. But as every mom knows, things don’t always go as planned. There are many reasons to supplement breast milk with formula, but one benefit of combination feeding is that it gives other family members a chance to feed and bond with baby.

Here are answers to some of the top questions about supplementing breast milk with formula:

Q: Is it okay to supplement my breastfed baby’s diet with formula?

If you’re not pumping and storing milk for later, formula is the best and most nutritional way to supplement breastfeeding. Supplementing breast milk with formula won’t reduce all the benefits of breastfeeding, but doctor knows best so speak with your pediatrician about your options and be sure to ask about formulas specifically designed for supplementing.

Q: Is it okay to breastfeed and formula feed at the same time?

It's perfectly okay to combine breastfeeding with formula feeding. If you find it hard to express enough breastmilk, combining breastfeeding with formula feeds is much better for your baby than stopping breastfeeds altogether. It's also an option that could work well for you if you’re going back to work.

Q: Will supplementing breast milk with formula affect my milk supply?

Milk supply depends on baby’s demand, so the less milk expressed, pumped or nursed, the less milk produced. Supplementing one or two bottles a week with formula shouldn’t slow milk production down, but if daily formula becomes part of a new feeding routine, the milk supply will adjust accordingly.

Q: Will supplementing my breast milk with formula ruin breastfeeding for me?

Supplementing with formula will not necessarily decrease your milk supply if your breasts are stimulated with direct nursing, pumping or hand expression for each supplemental feeding. But, it is very important not to miss any breastfeeding or pumping sessions when supplementing.

Q: How do I know if my baby’s getting enough breast milk?

Unlike a bottle, you can’t easily determine how much milk your baby is getting when you’re breastfeeding. Here are some indications your baby might not be getting enough breast milk:

  • Latching is painful and hard to achieve
  • Unusually short or long nursing sessions
  • No noticeable weight gain
  • Baby seems fussy but lacks energy
  • Less than six wet diapers a day
  • Infrequent, dark, reddish-brown poops

If you’re worried about your little one’s eating habits, be sure to discuss them with your pediatrician.

Q: Is it okay to breastfeed during the day and formula at night?

Breastfeeding during the day and bottle-feeding at night can allow you to get more sleep since it lets your partner participate more in feeding your infant. If possible, have your partner or someone else feed your baby the bottles of formula at night. This minimizes the likelihood of your baby wanting a bottle instead of your breast during the day by letting them believe you only provide breast milk while others only provide formula.

If your baby typically eats several times throughout the night, replace one of the feedings at a time and gradually move toward having all the nighttime feedings from formula. If you have any specific questions or concerns about the process, contact your doctor or lactation consultant for advice.

Q: When can I start supplementing with formula?

Though formula can be introduced from the start, breastfeeding is the recommended way to begin nourishing your baby’s growth and development. When considering supplementing, many doctors and lactation experts suggest waiting until the milk supply and breastfeeding routine have become established (roughly 3-4 weeks) so that introducing a bottle doesn’t unsettle mom or baby. If concerned about weight gain or the amount of nourishment your baby is getting, consult your pediatrician about starting supplementation earlier.

Q: Does it matter which formula I choose to supplement with?

With so many options out there, it can be easy to get lost in a sea of formulas. There are a few things you may want to look for when choosing a formula.

  • DHA, an important fatty acid that is naturally found in breast milk and supports both brain and eye development.
  • MFGM helps support your baby's cognitive development and is a naturally occurring membrane in breast milk.
  • Choline which aids in infant brain development
  • Calcium to support bone development
  • Some formulas also contain lactoferrin, an immune-supporting protein found in breast milk.

Q: How do you supplement breast milk with formula?

It’s important to ease your little one into bottle feeding. Experts suggest introducing the bottle gradually, starting with the feeding time your baby is least interested in. Once that routine is established, continue with the baby’s second least interested feeding session, and so on.

It’s suggested that the first bottle feeding take place when your baby is alert, but not too hungry. Don’t fret if your baby doesn’t take to the bottle right away. It can take some getting used to. It may also be easier if a partner or another family member offers the bottle, as it’s only natural for baby to associate mom with the real deal.

Q: Can I mix breast milk and formula in one bottle?

You shouldn’t mix the two. It’s best to start the feed with pumped breast milk, and if your baby still seems hungry, switching to formula. As an added benefit, doing it this way will ensure you don’t waste breast milk.

Q: How will supplementing with formula affect my baby?

If formula becomes your little one’s primary form of nutrition, they may start refusing the breast as eager eaters may like how a bottle might deliver their meals faster. Breast milk also digests easier than formula so many babies feel fuller with supplementation and can go longer between feedings. You will also notice a change in bowel movements, as they may have odor, appear browner in color and occur less frequently throughout the day.


Supplementing breast milk with formula can be a great option for many families and it’s a valid, healthy option for your rapidly developing little one. For more information on your little one’s specific feeding needs, always talk to your pediatrician.