For starters, smoking has been shown to increase bioavailability, which is the proportion of a drug when it enters the body’s circulatory system. When medications are administered in ways other than intravenously, the bioavailability rate naturally drops. This is due to incomplete absorption and what’s known as first-pass metabolism — when the concentration of a drug is reduced before it reaches the circulatory system.
Smoking has been shown to increase absorption. One study, Human Cannabinoid Pharmacokinetics published in 2017, states that “smoking provides a rapid and efficient method of drug delivery,” although the bioavailability can vary broadly based on how the CBD is smoked (duration, spacing of puffs, hold time, and inhalation volume).
When smoking or vaping CBD, the cannabinoids are sent directly to the lungs before being rapidly absorbed into the bloodstream and put into circulation throughout the body. It reaches peak concentrations in plasma within 3 minutes after consumption, meaning the effects can be felt almost directly after use.