My son was on this years ago due to allergies to other types of formula. He cried nonstop til he was 3 months old. The doctor kept telling me it was colic, but finally we figured out what it was. As soon as we started this, the crying stopped and he was happy! The taste is different and we were told to gradually introduce it over a 24 to 48 hour period. If you are giving 8 oz in a bottle, mix 6oz old formula with 2 oz of nutrimagen. I did this for 2 feeds and then gradually reduce the old formula and increase the nutrimagen. This will give your LO a chance to adjust to the taste without it being overpowering to him/her. Good luck.