Suppository

A suppository is a solid, single-dose form that is inserted into the rectum or vagina, where it melts or dissolves at body temperature and releases its contents.

Suppositories are made by dissolving the active ingredient in a base such as cocoa butter, hydrogenated vegetable oils, or polyethylene glycol, then molding it into a bullet or oval shape. The rectal route is used when swallowing is difficult, when a compound is broken down by stomach acid, or for local effect. Blood from the lower rectum partly bypasses the liver, so first-pass metabolism is reduced, though absorption varies with placement and formulation.

Cannabinoid suppositories are sold in some markets and are the subject of occasional discussion, but published pharmacokinetic and clinical data on rectal or vaginal cannabidiol are sparse, and early animal work suggests that absorption of some cannabinoids by this route can be poor. Claims about rapid or complete absorption should be read with that gap in mind. This entry describes the dosage form for educational purposes; questions about using any product this way belong with a clinician.