Hi there! Here is a link to the ingredient information (yes, it is fine to take with Zantac/Zyrtec): https://vagusnervesupport.com/ingredients/ (you may need to cut and paste). It is best taken in the morning on a basically empty stomach. If you can wait to eat until you have a bowel movement, or after an hour, that is best. I hope it is helpful for you! 😉