Various solutions have been proposed over the years since the problem was first named, but only a couple remedies work. One suggestion is to switch flavors. That hardly ever works. During an episode of olfactory exhaustion, all flavors are diminished to the vanishing point. No matter what flavor of e-liquid is used — nothing tastes like it’s supposed to. Sometimes every e-liquid tastes somehow off or even bad. More commonly, however, e-liquids have no taste at all, so changing flavors does nothing.
Another solution is dogged persistence — just vape through it. That’s difficult, however, because the condition is unpleasant and frustrating. Continuing to vape in spite of flavor numbness may actually extend and lengthen the condition.
The only sure-fire way to cure vaper’s tongue is to stop vaping entirely. How long? That varies, of course, but the general wisdom of a modest vaping fast — taking a day or two off from vaping — should do the trick and renew the ability to taste flavors. Still, no hard and fast rule applies as everyone is different and, I think it is safe to say, most vapers won’t want to be without a vape for a day or two.
Another suggestion is that vaping unflavored e-liquid, or even 100-percent vegetable glycerine (VG), with no added liquid nicotine, may shorten the duration of vaper’s tongue. The theory here is much like refreshing the palate between courses in a meal by eating or drinking something that perks up the olfactory senses, providing a change of pace.
Oral hygiene is often suggested: brushing the teeth or using mouthwash (Biotene is often recommended). These are good practices, but their benefits in combating olfactory exhaustion are dubious and minimal.
Sometimes the drying effects of propylene glycol (PG) as an e-liquid base are claimed as the culprit. That may or may not be true, as is the advice to drink more liquids. (Drinking liquids is a good idea, but it doesn’t prevent or cure vaper’s tongue.)