Video narration
What happens to a painkiller after you swallow it-does it work, then disappear? The tablet is absorbed into your bloodstream, then carried through your body. Before leaving, much passes through the liver, where your body changes it. That is the turn: it does not always act in its original form. The liver creates metabolites. A metabolite can stay active, become less active, or be inactive. Then the drug and its metabolites leave the body through the kidneys. This chain helps determine how strongly the painkiller works and how long it lasts. It also explains why the same dose can feel different from one person to another. Age, liver health, other medicines, and biology can change how quickly your body processes it. So why doesn't swallowed medicine simply act and vanish? Because metabolism is the body's transformation of a drug, mainly in the liver, before elimination.