Can I Switch From Breastmilk to Formula Cold Turkey?

A mom is bottle-feeding her infant baby

Breastfeeding experts do not recommend a sudden switch from breastmilk to milk formula, because babies need time to adjust to the new substances in formula and how they receive it, whether through a milk bottle or a cup. A gradual transition can be done at any age, but parents should observe well if their baby is adjusting well and tolerating milk formula. The amount of milk to be given depends on the baby’s age.

While breastmilk is definitely the best nutrition we could give your little ones, there are a number of valid reasons why this is not always possible.

It could be that the parent or the baby has a medical condition that does not allow for the use of breastmilk.

In some cases, psychosocial or cultural factors or personal beliefs call for using alternative milk instead.

After deciding to switch to milk formula, most parents are confused about how to proceed to the next step.

Is it okay to just switch breastmilk to formula milk at once? Or should it be done gradually? How do we know which formula is best? How can we tell if our little one is adjusting well?

Let’s find out more about these questions that parents commonly encounter when shifting their baby’s milk.

Can you switch baby’s milk cold turkey?

The Centers for Disease Control and Prevention (CDC) recommends weaning over a few weeks, not suddenly or within one day.

Your child is still adjusting to life outside the womb; changing their milk cold turkey will be an additional stress to these babies who have been used to the taste of breastmilk.

Let them get acquainted with the taste of formula first before diving headlong into the switch.

Another concern is the method of receiving milk.

Ever since they are born, babies are accustomed to the warmth and comfort of their mother’s breast and nipple.

Providing milk through a different way is also something they will need to adjust to, whether it’s a bottle nipple or a small cup.

Babies have a delicate gastrointestinal tract that has not yet fully matured.

A gradual transition from one type of milk to another will help your baby’s stomach and intestines get used to new proteins and substances from formula milk.

This will make it less likely for food intolerance or allergic reactions to occur.

When is the best time to wean to formula?

Because the World Health Organization (WHO) and numerous healthcare institutions recommend breastmilk for a minimum of 6 months and up to 2 years of age, there is no best time or period for switching to formula.

If the decision to switch was due to unexpected or urgent circumstances, then it’s best to start the gradual transition now.

If you have a specific date or week where you would like to switch to formula, start the transition 2-4 weeks earlier.

How to transition my baby from breastmilk to formula

How do I start the transition?

If you can still breastfeed, then slowly replace breastfeeding with formula feeds over the course of a few weeks.

Start by replacing one feeding session (the same one per day) with formula milk for one whole week.

If your baby seems to adjust well, then pick a second feeding session to replace for the following week, and so on, until you’re able to replace all feeding sessions with formula.

What kind of formula milk should I give?

Nearly all milk formula brands have a range of products labeled according to age group.

A baby bottle with prepared formula milk in it

Choose a well-established formula brand that fits your child’s age, and only buy from legitimate sources.

When buying online, ensure that the store you are purchasing from is licensed to distribute these products.

How much milk should be given per feed?

This will largely depend on age.

According to the American Academy of Pediatrics (AAP), a newborn may need only 2-3 ounces per feed every 3-4 hours, 4 ounces every 4 hours for a one-month-old, and up to 6-8 ounces every 6 hours for a six-month-old.

A rough estimate based on your baby’s weight would be 2.5 ounces per pound.

Each baby has their unique feeding habits, so these are not rules that you need to strictly follow.

If your child is at least 6 months old, don’t forget to supplement their feedings with mushy or solid foods, depending on their age and developmental stage.

For toddlers, 1 year old and above, try slowly introducing plain whole cow’s milk or fortified unsweetened soy milk.

How to know if switching to formula upsets babies

A mom is bottle-feeding her infant son, who she is gradually transitioning from breastmilk to formula milk.

Switching to formula cold turkey increases the chances that your baby will not tolerate formula milk well.

Some signs of this intolerance include being extra fussy or irritable, difficulty sleeping throughout the night, and rejecting the milk bottle or cup.

For some babies who are switched gradually, these symptoms may also develop, but not as frequently as those who switch cold turkey.

Formula milk is not as easily digestible as breastmilk, so several infants become constipated at first.

Don’t worry too much, as this could also happen when you introduce mushy and solid foods.


My baby seems to be allergic to the formula I bought. What’s the best brand to switch from breastmilk?

While most milk formula brands are safe for infants, there are cases when a baby’s immune system reacts to substances in the formula, leading to vomiting, diarrhea episodes, or rashes.

Try hypoallergenic milk formulas. For children at least one year of age, try shifting to soy-based milk products.

However, it’s best to seek consultation with your family doctor or pediatrician.

I don’t want to breastfeed, but I’m uncomfortable with formula. What are other alternatives to formula milk?

You can try getting donated breastmilk if this is available in your area.

Donated expressed breastmilk offers the same benefits as your own breastmilk without the troubles of breastfeeding your baby.

You can give this milk in a cup or a bottle, like formula milk.

Note that it may be hard to procure donated breastmilk as premature babies are given priority for this.


Switching milk cold turkey is not a good idea — it’s still better to make a gradual transition unless it’s a medical emergency (for either the baby or the mom).

During the transition process, guardians should note any signs that the baby is unable to tolerate formula milk. Whenever in doubt, it’s best to reach out to your pediatrician.

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Sarah is a healthcare writer, motivated by her love of reading books while growing up. She took up human biology and further studies in medicine, in order to fulfill her passion for helping kids. While she isn't a biological mother yet, she has taken two young dogs, named Indy and Obi-Wan, under her wing. She would love to someday travel the world and meet kids from different cultural backgrounds.

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