Area under the concentration-time curve (AUC)

Area under the concentration-time curve is a pharmacokinetic measure of total exposure to a substance in the bloodstream over a period of time.

When researchers draw blood at intervals after a dose and plot concentration against time, the resulting curve rises to a peak and then declines. The area beneath that curve, calculated mathematically, summarizes how much of the substance the body was exposed to and for how long. AUC is usually reported alongside maximum plasma concentration and time to peak, and it is the standard basis for comparing bioavailability between formulations or between fed and fasted conditions.

In cannabidiol research, AUC is the number most often used to show how much a fatty meal or a different carrier changes exposure. Two products with the same milligram content can produce quite different AUC values, which is why researchers say exposure is formulation-dependent. Readers encounter the term in study abstracts and in regulatory documents. It describes what happened in a study population and does not translate into a recommendation for any individual.