First-Pass Metabolism

Anything you swallow is absorbed in the gut and carried straight to the liver, which chemically alters much of it before the rest moves on to the body. CBD is fat-soluble and the liver works on it heavily, so a swallowed serving arrives in the bloodstream in a smaller amount than the label number suggests. A 2018 systematic review of human CBD pharmacokinetics (Millar and colleagues, Frontiers in Pharmacology) cites oral bioavailability of 13-19% from earlier animal work, and says plainly that human data on the question is thin. Read any single percentage as a rough range, not a promise.

The tissue under the tongue is thin and rich in small blood vessels, so a dose held there can pass into circulation without going through the gut first. That is the logic behind sublingual use. The same review also found that peak CBD levels are higher when CBD is taken with food and in lipid (fat-based) formulations, which is part of why oils are the common format. What no one has settled is exactly how much better any one route performs for any one person. Absorption varies with the individual, the carrier oil, and whether you have eaten.

In practice, we keep it simple. Place the drops under the tongue, hold them there for 60-90 seconds, then swallow. Our oral drops are hemp extract in organic coconut-derived MCT oil, made for this method, and we do not market them as nano CBD. Start with a small serving, give it a few days, and talk to your doctor if you take medications, because the liver enzymes that process CBD also process many prescriptions.