Bioavailability

bioavailability

Bioavailability is a measure of how much of a substance actually reaches the bloodstream or the body site where it needs to work after you take it. When you swallow a pill, eat a food, or get an injection, not all of the active ingredient may get where it needs to go. Some of it can be broken down in the gut, changed by the liver, or simply not absorbed through the gut wall. This concept matters because the benefits and side effects of medicines, vitamins, and supplements depend on how much is available to your body. A compound with low bioavailability might need a higher dose or a special formulation to work properly. Factors that change bioavailability include the form of the substance, whether it is taken with food, the health of the digestive system, and interactions with other drugs. Scientists and companies try to improve bioavailability with techniques like combining the compound with fats, using special delivery systems, or creating modified versions that are absorbed better. Doctors and pharmacists think about bioavailability when choosing doses and delivery methods so treatments are effective and safe. For everyday people, understanding this idea helps explain why some supplements seem ineffective or why two products with the same amount of an ingredient can have different results. If you're considering a new medicine or supplement, asking about its bioavailability can help you and your clinician make better choices.