How long after changing baby formula side effects

How long after changing baby formula side effects

How long after changing baby formula side effects

Changing a baby’s formula may trigger some side effects. This, however, does not mean you can feed your baby the same formula all through. Feeding is an important part of a baby’s growth. As a baby grows, so do their nutritional requirements. Due to this, some instances and conditions may cause you to transition or switch to a new formula slowly. In this post, we are going to explore how long after changing baby formula side effects.

Let us take it back a little bit for the sake of uniformity. Baby formulas are man-made attempts at mimicking the nutritional brilliance of natural breast milk. In short, they are nutrient-filled mixtures used to feed a baby.

The side effect reactions of these formulas differ from baby to baby

You know, that human physiology differs in more ways than you can imagine. True, babies have developing digestive organs, and these organs take time to get accustomed to new food.

However, the response time of the baby’s body differs from infant to infant. This difference in time could be attributed to a couple of factors that are highlighted below;

  • Underlying medical factors – especially allergies – could trigger an immediate response.
  • The type of formula you give to the baby could determine the response time frame.
  • The variety of food the baby has been exposed to in the past
  • The compositional ratio of the baby’s formula.

Having pointed those things out, it is quite obvious that we cannot specifically ascertain how long it would take the baby’s body to react to the formula.

However, it has been inferred from various observations that babies may experience immediate side effects that will last for about 3-5 days. In some other babies, their bodies would not react immediately.

If a formula change triggered any side effects, however, you would observe it between the periods of 5 -8 days.

NB: The above time frames cover the period when the side effects appear and disappear.
It is possible that these side effects are responsible for driving the need to change the baby formula in the first place. In that case, why don’t we examine some of these side effects?

Side effects of changing the baby formula

Allergic reactions – Some kids are naturally allergic to some food items. When you introduce these foods to their digestive tracts, their immune system automatically kicks against them.

The immune system reaction appears in the body as an allergic reaction. These reactions may be very severe, depending on how much intolerance the baby’s immune system has against the particular trigger.

Some common triggers include soy and wheat. Here are some of the common allergic symptoms that you observe in babies as a result of the formula change

  • Rashes
  • Extreme vomiting
  • Eczema
  • Swelling
  • Diarrhea
  • Diaper rash

Food Insensitivity

This is less mild in comparison to allergic reactions. In the case where your baby is insensitive to certain components of a new formula, you could give the baby a couple of days. After that, they would get used to it.

It’s just a matter of the digestive tract adjusting to those specific components. In the meantime, your baby could experience rashes and gassing.

Summarily, every side effect a baby experiences as a result of formula change can be classified as an allergic reaction or a result of temporary food insensitivity.

However, as mentioned earlier, despite these side effects, you cannot stick to just the same components and type of formula.

When should you switch your baby formula?

What are some of the indicators that you need to switch formula for your baby?

Frequent fatigue and tiredness

This is one of the most clear-cut indicators you need to switch formula for your baby.

The reason for this is simple; the current formula composition no longer meets your baby’s nutritional requirements.

That is, the food cannot produce the required amount of energy that will last your baby through a specific period of time. When you notice this, you should switch the formula as soon as possible.

Pale skin

You need to be observant enough to notice when your baby’s skin goes pale. This may be a result of iron deficiency. If that continues happening, it hampers blood production and nutrient circulation.

When you observe your baby’s skin is unnecessarily pale, you may want to consider switching the baby’s formula. To be sure, an iron deficient baby does not have its usual appetite.

Allergies and intolerance reactions

When you notice that a baby formula causes your baby to display prolonged signs of food intolerance – as discussed above – switch it. In the case of allergies, you are advised to switch formulas immediately. A particular one is a trigger. Allergies are in a league of their own, you have to succumb to the immune system, and there are no two ways around it.

Unnecessary weight Loss

Of course, weight loss in babies is not exclusively caused by the need to switch formula.

However, a formula switch is the next probable course of action in the absence of an illness and other factors.

The explanation for this is simple; your baby loses weight because the formula can no longer support their normal weight.

Excessive Gassing and Wheezing

Gassing (and even wheezing) is normal in babies. Babies gas for literally any new introduction to their digestive system. However, if you notice these things more frequently than normal, the formula is due for a change.

In the case of wheezing, the formula could have been causing the baby to accumulate excess mucus in the respiratory cum digestive structures of their body.

Is it ok to switch baby formula back and forth

The answer to this question is in the affirmative. Looking at it medically and by surrounding circumstances, there is absolutely nothing wrong with switching back and forth between formulas.

So that you understand, switching back and forth between formulas means that you alternate between different formula brands and compositions. People do this for babies due to different reasons, and here are some of them;
When they are trying to figure out which taste the baby is biased to.

Remember, babies are just developing their sense of taste; they become selective of one over the other when they do.
Some switch back and forth due to financial constraints at some period in time

Some also switch formulas back and forth because of time. Some formulas take time to prepare, while some do not.

This causes parents to switch back and forth as time allows. Some switch back and forth because they try the one that perfectly fits the baby’s digestive system.

Irrespective of what reasons you have, there are some important things you need to know about switching formulas. Here are some of those things;

You should consult an expert in this case, a pediatrician

To enquire about the type of formula that is optimal for your baby’s development. A doctor would most likely not lead you wrong.

You can switch formulas back and forth, except your baby is intolerant to dairy products. For instance, some babies are lactose intolerant.

This is noteworthy because most formulas have an element of cow milk in them. You know the implications of that, don’t you?

You have to be careful of allergies and formula composition when switching back and forth.

You need to make sure the different formula brands are fortified with iron. This is important for the baby’s growth, blood production, and circulation.

Look out to see if your formula has carbohydrates as per its constituent

Finally, check out to see if these formulas have the right quantity of protein and the right protein type. Also, you must remember that the protein type is the same as the brand you are switching from.

This is important for ease of transition; since proteins, and contradictions are the major basis for allergic reactions.

However, in the instance whereby the previous formula brand triggered digestive intolerance or allergic reactions, you should try a new protein type. That way, you avoid encountering the same problems you faced with the previous formula.

How long does it take for a baby to adjust to formula change

As mentioned earlier, there are more differences in human body physiology than you can imagine. Due to that, there is no uniform timeframe for babies to adapt to the new formula.

In some babies adjusting may be immediate; it could be within a week; in some, it could be more than that.

For the sake of specificity, experts have sat down to determine the range of days it takes babies to adjust to a new formula. It was deduced that babies would normally take one to six weeks to adjust to a new formula.

So if by any circumstance whatsoever, your baby still shows some sign of discomfort after 6 weeks, you may need to stop using that formula.

In some babies, their digestive system adapts to new food straight up. However, in some babies, you may need to help them transition slowly. That way, their digestive tract has ample time to get used to the newcomers. Just in case,

let us see some tips to help your baby transition successfully – especially if a formula change is pertinent.
It is safer not to switch all at once. Instead, you should try to introduce the formula little by little.

Note, however, that these tips are only applicable when the brand you are switching from does not trigger allergies in your baby. If that is the case, you should try a full switch immediately. It is safer that way.

Best practices dictate that you start with a 3:1 proportion. For example, if you add three spoons of the old formula, you add one spoon of the new formula.

On the second day, you can try mixing the two brands in equal proportion. For example, adding two spoons from the old formula adds two spoons from the new brand.

On the third, you can mix the formulas in a ratio of 1:3. So if you add a spoon of the old formula, you should add three spoons of the new one.

On the fourth day, you can go all out. By now, your baby’s digestive tract should have recognized the new formula.

It should have initiated a process through which it can digest the things that are foreign to it. If you like, you can try the above with a two-day interval in between. It is all according to your discretion.

Milk Allergy in baby symptoms

Milk allergies are the responses produced by a baby’s immune system to the protein in milk and other related food. Don’t be surprised; this allergy is common in babies that are not well breastfed. Essentially, when a baby’s immune system triggers some responses to cow milk and anything made with it, the baby has a milk allergy.

During your post-natal days, you must have been told that breast milk is the best food for babies. That is true; formulas are only as good as a close alternative.

However, you may have been thinking, instead of breast milk and formula, why not feed the baby with conventional milk? Yeah, that looks right on the surface; it’s all milk.

However, there are huge distinctions between the chemistry of milk, formula, and breast milk in the true sense of it. Just so you are sure, let us discuss milk allergies.

In this case, we will discuss it with respect to the symptoms your baby would exhibit. Believe it, these would never happen in the case of breast milk and even formulas.

  • Bloody stools
  • Frequent vomiting
  • Skin discoloration – the baby’s skin appears bluish
  • Abdominal pain and signs that are indicative of it. For instance, crying
  • Wheezing and coughing
  • Diarrhea
  • Swell in the mouth or esophageal area
  • Scaly skin
  • Rashes
  • Stuffed up nose
  • Hives
  • Colic

Like any other allergic reaction, the best way to take care of a milk allergy is to stop feeding the baby milk. You should also be careful not to feed these babies soy because allergy to milk means allergy to soy (in almost all cases)

Finally, if your baby is allergic to cow milk, goat’s milk would not be much of an exception so that you know how to streamline your choice of baby food.

When to switch formula because of gas

How long after changing baby formula side effects

Gassing is usually a result of your baby taking in too much air. However, formulas can trigger this too. In the case of a formula, you need to switch if you observe that your baby has been gassing excessively. Excessive in context means that the gas release occurs frequently and causes visible discomfort to the baby in question.

By the time you start noticing some of the signs below at unnecessary intervals; you may need to switch formulas:

Constant burping

Burping could occur when the baby’s digestive tract tries to rid itself of gas. Parents could also trigger it; you could sometimes be advised to burp your baby after you’ve introduced them to a new food.

However, if you start to notice constant burping, spitting, and hiccups between short intervals, that is a sign that the baby’s formula needs to be changed.

At that point, if you don’t, it could cause severe discomfort to the baby.

Read Also:

Switching From Breastfeeding To Formula at 2 Weeks

How Do I know If The Formula Is Right For My Baby


Bloated belly

By the time extra gas gets trapped inside the baby’s stomach, it obstructs the flow of another stomach liquid-like gastric juice – and causes unusual bloat.

What you will observe as a parent is that your baby’s stomach swells unnecessarily after each meal.

If that is the case, you need to switch the baby’s formula as soon as possible.


Babies get fussy due to any slight sign of discomfort. So, it can be challenging to tell if it is a result of excess gas.

However, you should note that when babies cry due to discomfort from excess gas, the cries sound sharp. Other than that, the baby would indicate other signs of discomfort, like fist clenching and eyes closing.

You should also observe if the baby is red-faced and is grunting. When you observe all these, you should switch the baby’s formula.


Farting in itself is healthy and normal. However, if your baby does not know facts, it is a major health challenge.

But what happens if you notice that our baby does this about 15-20 times a day? Of course, that is way too much.

However, this is usually the case if the baby has difficulty digesting the current formula. Therefore, you may need to switch the formula as soon as possible.


Healthy formula culture is equivalent to raising a healthy baby. As a parent, you have to pay careful attention to the kind of food your baby consumes. Even as an adult, some food items are not compatible with your digestive system. So also is your baby. You must make sure to have your eyes and your eyes open to changes and reactions when you feed your baby. Do not forget that formulas are the perfect building blocks for transitioning into purees and solid foods. So you should make sure to do it right.

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