Abstract Bioavailability, the degree and rate at which a substance is absorbed into the bloodstream and becomes available to its target site of action, is a critical factor in the efectiveness of medications and the utilization of nutrients. This article provides an overview of bioavailability, exploring the factors that influence it, including the route of administration, chemical characteristics of the substance, and individual variations in metabolism. The route of administration plays a ... Bioavailability simply means the fraction of administered drug that reached the systemic circulation (blood). It can range from 0% (no drug) to 100% (all of the administered drug). The adjectives “absolute” and “relative” are commonly added to the bioavailability term. Bioavailability refers to the extent and rate at which the active moiety (drug or metabolite) enters the systemic circulation, thereby accessing the site of action. Bioavailability is the amount to administrated drug that is used by the body. It is only possible to get the therapeutic effects of any drug when the drug can be absorbed by the body, so bioavailability is the key to making an enhancement that delivers proven benefits.
