Combining Breast and Formula Feeding for Your Baby

Woman feeding a baby at a sidewalk cafe

Gary John Norman/Getty Images

One of the coolest parts about breastfeeding is that it works on a supply and demand system. So, in other words, your body literally "learns" how much your baby will need to eat and will produce that much milk for your baby. Of course, it can take time to produce the amount of milk supply your baby needs and different factors, such as genetics, diet, stress, or illness, will affect your supply as well.

And in some cases, a woman might simply need to supplement her baby because of reasons other than personal preference. But whatever your reason may be, if you're hoping to combine breast and formula feeding, your body will adapt to make milk when you want it to, but here a few tips to help make that happen.

Establish Breastfeeding First

Even if you know you want to add formula feeding into the picture at a later point, it is best to start off with exclusive breastfeeding first. Not only will this ensure that your baby learns how to effectively breastfeed, but it will establish an adequate milk supply for your baby. It is much easier to taper down that supply when you're ready to add in formal feeding than try to have your body produce more milk. If you add in formula feeding right away, your body might not make enough milk, your baby may not suckle effectively enough, which will further discourage milk production, and you both may get frustrated very early on.

You should plan on exclusively breastfeeding for four to six weeks in order to build up your supply and establish a good breastfeeding routine with your baby.

Drop Breast Feedings One at a Time

Once breastfeeding has effectively been established and you have determined that you would still like to continue with mixed feedings, you can eliminate one breastfeeding at a time and replace it with a formula bottle. Many mothers might find it convenient to try to replace the nighttime feeding with a bottle, as dad or a partner might be able to feed the baby that way, giving her some much-needed rest. To prevent engorgement, you could hand-express extra milk, but be careful not to stimulate the breasts too much, as that could make you produce more milk. 

Be Flexible

You might have to experiment with different types of bottles or formulas to help your baby adapt to mixed feedings successfully and your baby might prefer breast over a bottle at certain times of the day. For instance. we had more trouble getting my babies to take bottles when they were especially sleepy since they just wanted the breast (more for comfort).

You may have to try different times of the day before finding a routine of mixed feeding that will work for all of you.

Be Prepared for Changes in Your Baby

Because the composition of breast milk and formula is so different, introducing formula to a strictly-breastfed baby may cause some changes in the baby's bowel movements. Breast milk has a much different microbial make-up than formula, so don't be alarmed if your baby's poop suddenly changes color. If your baby seems uncomfortable, is spitting up more, or seems constipated, you might want to speak with your care provider if mixed feeding is right for your baby or about trying a different type of formula.

Was this page helpful?
Article Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Nielsen SB, Reilly JJ, Fewtrell MS, Eaton S, Grinham J, Wells JC. Adequacy of milk intake during exclusive breastfeeding: a longitudinal study. Pediatrics. 2011;128(4):e907-914. doi:10.1542/peds.2011-0914

  2. Guaraldi F, Salvatori G. Effect of breast and formula feeding on gut microbiota shaping in newbornsFront Cell Infect Microbiol. 2012;2:94. doi:10.3389/fcimb.2012.00094