Dissolving Medicine Under the Tongue

This is called “sublingual administration,” as “lingual” generally refers to the structures of the tongue and mouth.

There is a large mucous gland under the tongue that supplies saliva to the mouth. Anything that comes into contact with this gland is absorbed into its capillaries, then into the veins of the face. This gives medication a direct path to the bloodstream.

When medicine is swallowed instead, it has to survive the intestinal tract – bile, stomach acid, liver metabolism, etc. Our digestive system is hostile by design. Its entire purpose is to break down and filter food, and that sometimes works against us when it comes to medication.

The disadvantages of sublingual administration is that it can be too sudden and erratic. If you swallow a pill, a pharmacist knows roughly how long it will take to break down, and once you swallow it, you can’t affect that at all – you can’t make it break down any faster or slower, so there’s a level of predictability there.

In contrast, holding a pill under your tongue can be awkward (opposed to a pill that you swallow in about one second), and just moving your mouth different ways, or drinking something, can dramatically affect how the sublingual medication is absorbed.

Why I Looked It Up

I was taking a Vitamin B12 supplement which was dissolved under the tongue. I had done this with other medications before, but suddenly wondered why.