when we eliminated soy and dairy from my daughter’s “diet” at 6 monhts old, it took at least 10 weeks before i saw her spitting up and reflux misery disappear. this was after 6 months plus of trying each reflux med (ppi and acid reducer) (except zegerid) in combo and by themselves. i wished i had considered mspi as a first line…have you tried carafate for those extremely miserable days? worked like a dream for us, but we only used it as needed and continued zantac even after the offending proteins were out of her system. still had hard days, just much less barf.