Sprays and drops taken under the tongue are becoming more common in the supplement world. Here's the reasoning behind the format.
The tissue under your tongue is rich in blood vessels, allowing certain compounds to absorb directly into the bloodstream rather than passing through the digestive system first.
Digestion can break down or reduce the bioavailability of some compounds before they ever reach circulation. A sublingual route is positioned to reduce that loss.
Sublingual formats require holding the liquid in place for a short period, which is a different habit than swallowing a capsule. For some people that's a minor inconvenience; for others it's actually more convenient than another pill.