Dose (biochemistry)
A dose is a measured quantity of a medicine, nutrient, or pathogen that is delivered as a unit. The greater the quantity delivered, the larger the dose. Doses are most commonly measured for compounds in medicine. The term is usually applied to the quantity of a drug or other agent administered for therapeutic purposes, but may be used to describe any case where a substance is introduced to the body. In nutrition, the term is usually applied to how much of a specific nutrient is in a person's diet or in a particular food, meal, or dietary supplement. For bacterial or viral agents, dose typically refers to the amount of the pathogen required to infect a host.
In clinical pharmacology, dose refers to the amount of drug administered to a person, and dosage is a fuller description that includes not only the dose (e.g., "500 mg") but also the frequency and duration of the treatment (e.g., "twice a day for one week"). Exposure means the time-dependent concentration (often in the circulatory blood or plasma) or concentration-derived parameters such as AUC (area under the concentration curve) and Cmax (peak level of the concentration curve) of the drug after its administration. This is in contrast to their interchangeable use in other fields.