Glossary
Sublingual
Updated:
Sublingual means held under the tongue. Tincture instructions usually say to hold the oil there for a minute or so before swallowing so some CBD crosses the thin mucosa directly, bypassing first-pass liver metabolism. Pharmacokinetic data show sublingual and oromucosal routes reach the bloodstream faster than swallowing alone.
The floor of the mouth has a thin lining with a rich blood supply. A compound held there can pass directly into veins that drain to the heart, skipping the stomach, intestine and the liver's first-pass metabolism. Sublingual dosing of hemp tinctures is built on that route.
In practice, most of a tincture dose is still swallowed. The 2018 systematic review of CBD pharmacokinetics compared sublingual drops, an aerosol and a nebulizer in one small study and found that inhaled routes reached peak concentration faster and higher, while sublingual drops gave a lower, slower peak (Millar 2018). Oromucosal sprays, which deliver to the cheek and under the tongue, showed exposure that rose about 5 fold when taken with food, which points to a large swallowed fraction (Millar 2018).
Holding the oil longer increases the mucosal share. Most labels suggest a minute or more, though no published study fixes an optimal time.
Carrier oil matters as well. Lipid excipients raise systemic exposure for the swallowed portion (Zgair 2016). Sublingual delivery works best with a concentrated oil, small volume and no immediate food or drink afterward.
Sources
- A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans (Front Pharmacol, 2018) PubMed (accessed 2026-10-13)
- Dietary fats and pharmaceutical lipid excipients increase systemic exposure to orally administered cannabis and cannabis-based medicines (Am J Transl Res, 2016) PubMed (accessed 2026-10-13)