On the internet sellers of liquid mushroom extracts and tinctures usually recommend to take the product sublingual (under the tongue) instead of just swallowing it. If you have to believe them this is the best way to benefit from their product, and the main reason to choose a liquid mushroom product in the first place (why a liquid mushroom extract is actually not recommended at all you can read here).
Despite their convincing-sounding arguments they are wrong. Although for many drugs and supplements sublingual administration is indeed better, a mushroom product has unique properties that should be taken into account. This is science, not just an opinion.
First of all, the main bioactive compounds in mushroom extracts are beta-glucans. When taken orally, intestinal absorptive cells (enterocytes) facilitate the transportation of beta-glucans and similar compounds across the intestinal cell wall into the lymph, where they begin to interact with macrophages to activate the immune function.
Sublingual (under the tongue) or topic administration of beta-glucans is not effective because of the large size of bioactive beta-glucans. These are huge macro-molecules.
Compare it to trying to fit a foot size 9 in a shoe size 8 – it can’t be done. You would have to keep the glucan-containing liquid under your tongue for hours in order to get something in your system. Which is impractical, not to say undoable.
Second, beta-glucans and most other bioactive mushroom compounds found in properly extracted mushrooms are not affected by the stomach acid, and if you take them on an empty stomach (at least 30 minutes before meals) the therapeutic effects are just perfect. There is nothing to gain by sublingual administration.