I am SO glad that I found these reviews. I used Arm & Hammer in the past, never had a problem. This extra whitening was on sale so thought I would try. Started experiencing dry mouth first. Woke up, tongue stuck to mouth. Then in a few days, white coated tongue, but nothing too bad. A few more days and thought I had developed what I thought was thrush. I had blisters on the inside of my mouth, cracked lips, swollen red gums, swollen tongue, burning tongue, no taste on tip and sides of tongue. I thought it was just thrush, not related to the toothpaste. My mouth was so painful, that it was hard to brush with toothpaste so I just used warm water, flossed even though I was in agony. Rinsed. Mouth started to clear up, taste on the tip and sides of my tongue started coming back, so I started using this toothpaste again, and MAN the next DAY the sores on the underside of my tongue came back!! I started to feel my tongue burn again! Outside of my mouth, corner of my lips started cracking again, I can barely talk. I searched the internet on Arm & Hammer extra whitening and these reviews came up. I am throwing the product in the TRASH! They need to place a warning on the label.