Funny it was just the opposite for me. I had been taking ranitidine (prescription zantac) 150 mg twice daily for years, and when I started intermittent fasting , one meal a day, and added ACV, I haven't even had to take one dose! No more heartburn. That may be due to IF, or may be due to ACV. I take mine ice cold in lemon flavored seltzer water. It's delicious.