Mixing Breast Milk and Formula

Combining Breast Milk and Formula

Combination feeding baby 

(Physically mixing breast milk and formula in one bottle, is discussed lower on the page)

A combo of breast milk and formula is definitely a better option than ending the breastfeeding relationship altogether, as any amount of breast milk is better than none.

When is supplementation acceptable? 

It is not recommended to give your baby an artificial nipple, before four weeks of age. If you are worried about nipple confusion, you can always get your spouse or daycare provider to feed your baby via alternative feeding methods discussed here.

baby drinking from bottle, bottle fed baby, cute baby holding a bottle

When you start substituting breast milk for formula, your breast milk supply might decrease, unless you continue to empty your breasts by pumping.

Many mothers feed their babies a mixed feeding of expressed breast milk and formula when they return to work, this is perfectly okay, but it is possible to continue to feed a baby exclusively on breast milk. 

Many mothers decide to continue to physically breastfeed their babies only at night or only in the mornings. This is wonderful, to continue, even if partially.

Preventing Nipple Confusion

Partial Weaning

Breastfeeding issues that might influence the introduction of combination feedings

  • Not capable of pumping at work.
  • Mothers who feel that they don’t want to pump at work.
  • Baby is self-weaning.
  • Mom has an insufficient milk supply and has to supplement her breast milk with formula. This can be done by using an SNS, which is used to increase supply while breastfeeding and supplementing with formula or donor breast milk at the same time.

Will my milk dry up entirely with a breastfeeding bottle feeding combination?

No, if milk is removed from your breast, your body will adjust and start to produce just the right amounts for those times that you do breastfeed. 

Is it Safe to Physically Mix Breast Milk and Formula?

  • It is not recommended to put formula and breast milk in the same container. Why? Formula spoils much quicker than breast milk. Formula bottles should be discarded after an hour, whereas breast milk can be kept much longer, without being spoilt. This is to prevent the wastage of precious breast milk.
  • The best is first to feed your baby the breast milk and then feed him/her the formula; this way you know that none of your breast milk had gone wasted.
  • Do not ever mix formula with breast milk, instead of water! The concentration will be too intense for your baby’s kidneys, and your breast milk's composition will be changed.
baby drinking from a bottle, bottle feeding, bottle feeding breast milk

What if Baby is Refusing to Drink from a Bottle?

  • Sometimes, it is best to get someone else to offer the bottle to your baby. This is so that he/she does not expect to be breastfed.
  • Try to give him/her the bottle at night, in the dark.
  • Try different brands of teats, until your baby finds one that he/she prefers. Avent baby bottles have been found by many moms, to be the best of the natural baby bottles and nipplesUse alternative feeding methods instead of artificial nipples, if possible. 

Weaning from Breast to Formula

If you are decreasing your breastfeeding times and want to start mixing breast milk and formula, it should be done gradually, this will ensure that your body has the chance to adapt and will give your baby's tummy a chance to adapt. Mothers that add mixed feedings abruptly may develop mastitis, and their babies may develop some digestive issues.

Bottle-feeding and breastfeeding

by New mom (Barrie, Ontario, Canada)

"I am bottle feeding and breastfeeding my 8-day old baby. I get frustrated because I spend a good 30min to 1hr breastfeeding and still come out short.

My back aches already, and my nipples start to feel sore. I then add formula to top up the breast milk with 1 ounce - 1 1/2 ounce.

I don't understand what my baby wants after an hour of breastfeeding. (

It gets frustrating."

Re: I know it's frustrating

by: Jaclyn Pawlowski

"Love, I know it's frustrating. My 5 week old had several days of cluster feelings during his growth spurt, where he fed non-stop all day long.

Maybe this is a growth spurt. Do you have a breastfeeding center or lactation consultant you can see who could help guide you and make this less frustrating?

I saw one when my little one was 5 days old and it helped tremendously. They were very encouraging. The first growth spurt starts at 7-10 days. Are you keeping track of wet & dirty diapers? That will let you and the consultant or pediatrician know if he/she is getting enough milk.

If they are going through a growth spurt, he/she could be eating to stimulate the production of more milk. Another comes ~ week 2-3 & week 6.

If you need a break, you can try pumping and have someone else feed the baby. I did that too and it helped. My nipples were also very sore and the consultant prescribed me a topical antibiotic which helped me heal (took 4-7 days before it felt better) but well worth it!

Hang in there and good luck!"