Change in Formula – How long does it take a baby to adjust?

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change in formula - baby adjusts


This article is about how long it takes a baby to adjust to a change in the type of formula.

They don’t like this because they have grown used to one taste of the current formula, and now you’ve changed it, which will make them feel uncomfortable or unhappy.

It’s essential to take precautions like slowly introducing the new taste over time rather than all at once.

Read on to learn about what you can expect when you change formulas.

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Why should you change the Baby formula?

There are many reasons why you might need to change infant formula.

Here are a few:

1.As babies grow, they can no longer tolerate their current formula for one reason or another.

change in formula - baby adjusts

2.The baby is diagnosed with a medical condition, like an allergic reaction to cow’s milk-based formula, and needs to be on a special baby formula based on soy milk, goat milk, a Hypoallergenic formula, or a specialized formula.

3.Costs may force you to look for cheaper alternatives, as your child may require more formula as they grow. Initially, your baby would be full with smaller quantities, which would have costs in control. But once they grow, they need a lot more of the current formula, and these increased costs could put a strain on your finances.

4.You may want to switch from non-organic to organic formulas, which, as you know, are going to prove more beneficial to the child. However, this is an expensive formula. 

These formulas are lactose-free and generally used as a last resort for lactose-intolerant babies, those with severe allergies, or those who have severe colic with no relief from other formulas.

5.The baby may be deficient in iron or have vitamin deficiencies and may need an Iron-fortified formula.

Your family doctor might recommend a formula made from cow’s milk. Certain formulas are iron-fortified. These are usually advised by most doctors.

6.You may be wanting a switch in formula because you are getting a great deal from your supermarket.

However, you shouldn’t change to a new formula just because you got a deal. It’s a big transition for the most adaptable baby.

How do babies react to change in formulas?

Babies can be very sensitive to a formula switch. They might not like the change because they have grown used to one taste and now you have changed it, which will make them feel uncomfortable or unhappy. It’s important to take precautions like slowly introducing the new taste over time rather than all at once.

It would be best if you looked out for the following problems and signs during the transition period:

1. Change in stools and poop consistency – sometimes they will have loose stool or diarrhea

2. Stomach cramps, stomach aches, vomiting, and regurgitation, are also symptoms babies might show if they are not happy with their formula.  

3.Other symptoms are fussiness and gas

4.Improper sleeping at night

5.Makes faces as if they are in pain

6.Cries more frequently.

baby crying frequently

These problems can usually last for a couple of weeks after the change

If you have changed due to health reasons, then the child will adjust much better as they will start to feel better with the changed formula.

For example, if your child had a milk allergy due to cow’s milk, and you switch to a soy-based formula, the allergy will start to reduce, and the child will adjust faster.

If you have changed over to an organic one, there should not be much difficulty in adjusting.

For changes in Formula Brands, due to costs, adjustments should not be difficult as long as the type is the same.

How to introduce a new formula?

It is important to take precautions like slowly introducing the new taste over time rather than all at once.

You could give them a little bit of the new one in the day while continuing with the old one so that he gets gradually used to it.

Then check on any adverse reactions and keep increasing the amounts of the new formula till the baby has made a total switch.

You could also make the switch right away if your baby can take the change in his stride and is not too sensitive.

In cases related to health problems, you could also make the change at one stroke.

Can you mix the old and new formulas?

It is advisable not to mix as there could be problems and may not suit the child.

However, if you mix organic and non-organic ones, you could add a scoop of each to make it easier for your child.

But don’t mix cow milk-based formula with soy-based ones.

This could defeat the purpose of the change, and the health of your child would continue to be a problem.

Other things to consider

It would be best if you kept a thorough watch over your child for any changes in behavior or any other allergic reactions.

If the new formula is creating too many issues, even after 8 to 10 days, you can switch back to the old one.

You should also consult your Doctor in such cases.


It can take your baby a while to get used to a new formula, but up to 10 days is a good time to notice any adverse effects.

Expect to spend some time getting your baby used to the new formula and waiting for their body to give you a sign that everything is going great.

Don’t worry if the improvement isn’t immediate. Gradual progress and change are to be expected. Keep in touch with your Doctor and let them know about the progress of the switch so they can assist you if something more serious arises.

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Carrie Walters
Carrie Walters is a young mother of Nina and Tom, who along with her husband Jake is passionate about helping moms and families find modern solutions to common parenting and lifestyle questions. Together with a team of real moms and medical experts, this young couple share sound advice and proven tips to help make your life easier. They manage this blog along with other blogs and Youtube channels on similar topics