Drug absorption refers to the process by which a drug enters the bloodstream after administration. This process is crucial for the drug to exert its therapeutic effects. Factors such as the drug's formulation, route of administration, and the physiological conditions of the body can significantly influence absorption rates. Different routes of administration, such as oral, intravenous, or transdermal, affect how quickly and efficiently a drug is absorbed. For instance, drugs taken orally must pass through the digestive system, while intravenous drugs enter the bloodstream directly, leading to faster effects. Understanding these mechanisms is essential for optimizing drug therapy.