The menthol drops are just that, really strong menthol. The cool rush is a flavoring with a hint of menthol in it. I have tried
vaping just the menthol and it tastes like
vaping Vicks Vapor Rub, not very good. I even tried toning it down with a lot of PG and VG and some Loranne's (peppermint, spearmint and wintergreen) but since these all have oil in them, just a drop (they are really strong too), not a good idea to use anyway. These ended up being tossed and the reason for ordering the Cool Rush. With the base being the menthol it was just too much, could never get beyond the super strong Vics taste. I have found the menthol drops are best added to a flavored
juice, and just a tiny bit, maybe one drop. Gives a nice throat hit. Beyond that, I think it is just too much. The Cool Rush has a great taste, but does take a lot more than I expected. It is no where near Loranne's or any other flavoring I have tried as far as amount you have to use to get decent flavor. I have pretty much stopped messing with menthol and switched over to the Cool Rush and am getting much better results. Hope this helps.