I’ve been using this for several years. I go though 2 bottles a year. Because it’s herbal, it does lose some potency - so use it liberally. Which is a good thing. For those with a sensitive palate - it is very strong. I’m so happy not to be using an OTC medication.
It does burn a little in my mouth, but it works better and faster than anything else I've tried. The results are worth the temporary discomfort - and I don't use it unless I need to. After one bottle, I've ordered more so I don't run out this summer.