Hello D. Hayward,   Everyone reacts differently to medications. Some work more quickly than others. Nexium is a proton pump inhibitor. It blocks the production of acid.   Dr Todd Eisner addresses the subject of how quickly these medications work in this sharepost. Dr Eisner has also written a sharepost here about Nexium itself and users who might need a higher stronger dose.   Hope this helps somewhat. Online sites are great places to get information to help you ask all the right questions of your doctor, but can not take the place of your doctor's care and advice.   Take care and stay in touch. Let us know how you are doing!Vicki M