Carrier oil (MCT)

Cannabinoids are lipophilic. They dissolve in oil, not water, so almost every tincture and softgel uses a fat as the vehicle. The carrier sets the product's taste, shelf life and, to a meaningful degree, how much cannabinoid the body takes up.

Medium-chain triglyceride oil is the industry default. It is fractionated from coconut or palm kernel oil to keep only the shorter fatty acids, which makes it liquid at room temperature, nearly tasteless and resistant to going rancid. Hemp seed oil adds a grassy flavor and its own fatty acids but oxidizes faster. Olive and avocado oils are used for flavor or marketing reasons.

Fat is not just a solvent. A 2016 study found that dietary fats and pharmaceutical lipid excipients increase systemic exposure to orally administered cannabinoids, in part by routing absorption through the intestinal lymphatic system and around the liver (Zgair 2016). Human data agree: a systematic review reported about 5 times higher CBD exposure when dosed with food instead of fasted (Millar 2018).

Carrier oils also carry their own risk of oxidation and contamination, so a certificate of analysis for a finished tincture should cover the whole formula, not only the extract.