A small percentage of people may find that the Banjo lozenge irritates their mouth.
This is most likely doe to mechanical irritation (the large lozenge is rubbing against the inside of your mouth and your mouth isn’t used to it.) Such irritation will probably go away over time (your mouth gets used to the big lozenge.) However, if you find that the lozenge irritates your mouth, one way to lessen that irritation is to not move the lozenge around so much as you are using it. Just tuck it off to one side. It will then dissolve more slowly, but mechanical irritation will be minimized.
Another possibility is that certain ingredients in the lozenge, and not mechanical abrasion, may be the source of irritation. A small percentage of people have reported the development of mouth sores when using feverfew. These sores generally develop as a result of chewing feverfew leaves, and they go away on their own once feverfew use (leaf chewing) is stopped. While the amount of feverfew in Banjo is very small, it is possible that the same mouth sores could occur as a result of exposure to feverfew.
One alternative, if irritation persists or if mouth sores develop, is to switch to a liquid administration method. The Banjo lozenge can be dissolved to make a mild tasting, potentially less irritating ‘tea’, as described here.
If mouth irritation or mouth sores persist, use of Banjo should be discontinued.