We can’t transition to another formula. My daughter has sensory processing disorder affects her eating. She will only drink her formula out of a bottle because the taste is different in a cup. Now to change the taste of her formula is impossible . She had a bottle aversion at 5 months old which resulted in a feeding tube . We were able to get her to trust her bottle and get off the feeding tube . These formulas are so acidic that we were able to find the right combination that worked along with taking anti acid medication. Profree provides the extra calories she needs to now thrive.