A drug is any chemical or biological substance, synthetic or non-synthetic, that when taken into the organism's body, will in some way alter the functions of that organism. This broad definition can be taken to include such substances as food. However more strict applications of the word prevail in everyday life. In these cases the word "drug" is usually used to refer specifically to medicine, vitamins, entheogenic sacraments, consciousness expanding or recreational drugs. Many natural substances such as beers, wines, and some mushrooms, blur the line between food and drugs, as when ingested they affect the functioning of both mind and body. The word "drug" is etymologically derived from the Dutch/Low German word "droog", which means "dry", since in the past, most drugs were dried plant parts[citation needed].
Drugs are usually distinguished from endogenous biochemicals by being introduced from outside the organism. For example, insulin is a hormone that is synthesized in the body; it is called a hormone when it is synthesized by the pancreas inside the body, but if it is introduced into the body from outside, it is called a drug.
Legal definition of drugs
Some countries also defined what a drug is by law. In the United States, the Federal Food, Drug, and Cosmetic Act defines a drug as being an article "intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals" or an article "(other than food) intended to affect the structure or any function of the body of man or other animals." FDCA ?201(g)(1)
Medication
A medication or medicine is a drug taken to cure and/or ameliorate any symptoms of an illness or medical condition, or may be used as preventive medicine that has future benefits but does not treat any existing or pre-existing diseases or symptoms.
Dispensing of medication is often regulated by governments into three categories — over-the-counter (OTC) medications, which are available in pharmacies and supermarkets without special restrictions, behind-the-counter (BTC), which are dispensed by a pharmacist without needing a doctor's prescription, and Prescription only medicines (POM), which must be prescribed by a licensed medical professional, usually a physician.
Most over-the-counter medications are generally considered to be safe enough that most people will not hurt themselves if they are taken as instructed. In the UK, BTC medicines are called pharmacy medicines which can only be sold in registered pharmacies, by or under the supervision of a pharmacist. However, the precise distinction between OTC and prescription drugs depends on the legal jurisdiction.
Medications are typically produced by pharmaceutical companies and are often patented to protect their exclusive rights to produce them, but they can also be derived from naturally occurring substance in plants called herbal medicine. Those that are not patented (or with expired patents) are called generic drugs since they can be produced by other companies without restrictions or licenses from the patent holder.
Drugs, both medications and recreational can be administered in a number of ways:
Orally, as a liquid or solid (pill), that is absorbed through the stomach.
Inhaled, (breathed into the lungs), as a vapor.
Injected as a liquid either intramuscular or intravenous (put under the skin, into a vein or muscle tissue with the use of a hypodermic needle).
Rectally as a suppository, that is absorbed by the colon.
Vaginally as a suppository, primarily to treat vaginal infections.
Bolus, a substance into the stomach to dissolve slowly.
Many drugs can be administered in a variety of ways.
