bioavailable
Meaning of bioavailable: Bioavailable describes the proportion of a drug or nutrient that reaches the bloodstream intact and able to produce its intended effect.
Definition of bioavailable
Bioavailable describes how much of a drug, nutrient, or other substance that is taken into the body actually reaches the bloodstream in an active form, able to produce its intended effect, rather than being broken down, blocked from absorption, or eliminated before it can act. Bioavailability is often expressed as a percentage compared with the same substance given directly into the bloodstream, which is considered completely bioavailable.
A substance taken by mouth is described as orally bioavailable if a meaningful portion survives digestion and passage through the liver before circulating throughout the body. Factors such as a substance's chemical structure, how it is formulated, and interactions with food or other substances can all affect how bioavailable it is.
Bioavailability is an important consideration in determining appropriate dosing, since two forms of the same active substance can differ considerably in how much actually reaches general circulation.
Used in a sentence
The oral form of the medication was noted to be less bioavailable than its intravenous equivalent.
Good to know
Two products containing the same active substance can differ meaningfully in bioavailability depending on their formulation, a reason switching between certain brand and generic products is approached carefully.
Word origin
Where “bioavailable” comes from
Formed from Greek bios, meaning life, combined with available, from Latin valere, meaning to be strong or of worth.