The process of transitioning from one formula to another should be done under the guidance of your child’s pediatrician.

There are many reasons you might change your child’s formula. Some of them aren’t medical at all. The price may simply go up on the one you’re using and you decide to switch to a less expensive brand. For the purpose of this discussion, I’m going to focus on the medical reasons. I’ve listed some common medical reasons below.

1. Gas / Fussiness
2. Mucousy stool
3. Bloody stool
4. Vomiting / Poor weight gain
5. Constipation
6. Diarrhea

The method we’ve used to transition takes ten days. Every other day you add another feed of the new formula. So, for example, you might do four feeds of the old formula and one of the new for the first two days. Then, on the third and fourth day, do three feeds of the old and two of the new. This minimizes the discomfort your child experiences due to the transition itself. I recommend the following schedule. “O” stands for old formula and “N” stands for new formula:

Day 1 & 2: O O N O O
Day 3 & 4: O N O N O
Day 5 & 6: N O N O N
Day 7 & 8: N N O N N
Day 9 & 10: N N N N N

Depending upon the reason you’re transitioning, you may have a difficult time knowing if the transition is working. As you can see above, it takes us about a week and a half to transition from one formula to another. You’re still feeding the old formula, which was causing issues, until days nine and ten. It’s reasonable for it to take three to four weeks to see the full benefits of the new formula. In our experience, it can take up to six weeks.

It’s extremely important, so much so it can’t properly be conveyed through text, the transition is allowed time to work. Changing formula alone can cause gastrointestinal discomfort. If you change frequently enough through several different formulas it has the potential to make your child significantly sicker than they were feeling to begin with.

Please consult with your pediatrician and the applicable specialists before making any changes to your child’s feedings. Even if the transition does solve the problem, it may still be necessary to run tests and determine the underlying cause. Allergies, as an example, can worsen over time if they’re not removed from your child’s diet and your child continues to have reactions. There is evidence that suggests removing an allergen early in your child’s life may eliminate the allergy entirely.

Do not switch your child off of formula onto any other diet except in coordination with your child’s pediatrician and/or applicable specialists. Cow’s milk, almond milk, and other different types of milk do not have adequate nutrition alone to be used in place of formula.