The Hair Loss Encyclopedia
proportion of a substance that enters the bloodstream and works
Bioavailability refers to the proportion of a drug or other substance that enters the bloodstream when introduced into the body and is thus able to have an active effect. For example, if you take a vitamin pill, bioavailability determines how much of that vitamin actually gets absorbed and used by your body, rather than being excreted. This concept is crucial in pharmacology and nutrition because it affects the efficacy of medications and supplements.