Hello @Jovdp, follow arpie's suggestions - I had severe (crater size) mouth ulcers a few years ago and no 'treatments' made any difference although rinsing with warm water and bi-carb soda eased the pain. I eventually figured out the all food had to be 'soup'. I also located some 'fat' drinking straws and used to position the straw towards the back of my throat - basically this meant I wasn't starving although I lost quite a few kilos. I've been on Herceptin and exemestane for almost ten years and I've decided the ulcers are a response to the 'stress', ie, immune system compromised. I hope this helps as mouth ulcers are an 'affliction', ie, **!!etc painful and debilitating.