I agree, it seems better to leave them alone. They seem to usually break open on their own, but maybe as the above post says, if you keep them moist, maybe they don't do this? I have a small scar on my upper lip now from not leaving one run its course, and it took the longest to heal compared to other blisters I had at the same time. And I think had I left it be I wouldn't have gotten those other blisters. But when you have a giant throbbing blister on your mouth I can see how it would make sense to drain it! I just think over the long run its better to avoid them as much as possible. I have found lemon balm is helpful for relieving pain. I also mean no disrespect to other remedies people have found to work for them, but I found for myself Colliodial Silver made me feel ill, and also seemed to turn my complexion a grayish color! I don't recall taking tons of it, just what was suggested on the bottle, so I think maybe it works for some, but maybe not others. Perhaps topically its different than taking it internally, so I may try it again this way if I end up with cold sores again.