Caffeine, contained in coffee and other beverages, is the most widely used psychoactive drug in the world. 90% of North American adults consume the substance on a daily basis.[1]
Uncoated aspirin tablets, consisting of about 90% acetylsalicylic acid, along with a minor amount of inert fillers and binders. Aspirin is a pharmaceutical drug often used to treat pain, fever, and inflammation.

A drug is any substance (other than food that provides nutritional support) that, when inhaled, injected, smoked, consumed, absorbed via a patch on the skin, or dissolved under the tongue causes a physiological (and often psychological) change in the body.[2][3]

In pharmacology, a drug is a chemical substance of known structure, other than a nutrient of an essential dietary ingredient, which, when administered to a living organism, produces a biological effect.[4] A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to treat, cure, prevent, or diagnose a disease or to promote well-being.[2] Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis.[5] Pharmaceutical drugs may be used for a limited duration, or on a regular basis for chronic disorders.[6]

Pharmaceutical drugs are often classified into drug classes—groups of related drugs that have similar chemical structures, the same mechanism of action (binding to the same biological target), a related mode of action, and that are used to treat the same disease.[7][8] The Anatomical Therapeutic Chemical Classification System (ATC), the most widely used drug classification system, assigns drugs a unique ATC code, which is an alphanumeric code that assigns it to specific drug classes within the ATC system. Another major classification system is the Biopharmaceutics Classification System. This classifies drugs according to their solubility and permeability or absorption properties.[9]

Psychoactive drugs are chemical substances that affect the function of the central nervous system, altering perception, mood or consciousness.[10] They include alcohol, a depressant (and a stimulant in small quantities), and the stimulants nicotine and caffeine. These three are the most widely consumed psychoactive drugs worldwide[11] and are also considered recreational drugs since they are used for pleasure rather than medicinal purposes.[12] Other recreational drugs include hallucinogens, opiates and amphetamines and some of these are also used in spiritual or religious settings. Some drugs can cause addiction[13] and all drugs can have side effects.[14] Excessive use of stimulants can promote stimulant psychosis. Many recreational drugs are illicit and international treaties such as the Single Convention on Narcotic Drugs exist for the purpose of their prohibition.


In English, the noun "drug" is thought to originate from Old French "drogue", possibly deriving later into "droge-vate" from Middle Dutch meaning "dry barrels", referring to medicinal plants preserved in them.[15] The transitive verb "to drug" (meaning intentionally administer a substance to someone, often without their knowledge) arose later and invokes the psychoactive rather than medicinal properties of a substance.[16]

Other Languages
Afrikaans: Dwelmmiddel
Alemannisch: Droge
አማርኛ: መድኃኒት
asturianu: Droga
تۆرکجه: دواء
বাংলা: ঔষধ
Bân-lâm-gú: Io̍h-bu̍t
bosanski: Droga
brezhoneg: Dramm
català: Droga
Cymraeg: Cyffur
Deutsch: Droge
eesti: Droog
español: Droga
Esperanto: Drogo
euskara: Droga
فارسی: دارو
føroyskt: Rúsevni
français: Drogue
Gaeilge: Druga
galego: Droga
Ido: Drogo
Bahasa Indonesia: Obat
interlingua: Droga
italiano: Droga
עברית: סם (כללי)
ಕನ್ನಡ: ಡ್ರಗ್
Kreyòl ayisyen: Dwòg
kurdî: Tiryak
Latina: Medicamentum
македонски: Дрога
Bahasa Melayu: Dadah
Baso Minangkabau: Ubek
Mìng-dĕ̤ng-ngṳ̄: Iŏh
မြန်မာဘာသာ: ဆေး
Nederlands: Drug
日本語: 薬物
occitan: Dròga
ਪੰਜਾਬੀ: ਡਰੱਗ
Patois: Jogz
polski: Używka
português: Droga
română: Drog
Scots: Drog
shqip: Droga
sicilianu: Droga
සිංහල: බෙහෙත්
Simple English: Drug
српски / srpski: Дрога
srpskohrvatski / српскохрватски: Droga
Basa Sunda: Ubar
svenska: Drog
тоҷикӣ: Дору
Tiếng Việt: Chất gây nghiện
ייִדיש: דראג
中文: 药物