Drug
![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]](/Images/godic/202501/10/A_small_cup_of_coffee2908.JPG")
![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.](/Images/godic/202501/10/Aspirine_macro_shot2908.jpg")
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![Flowering San Pedro, a psychoactive cactus.[22] Today most mescaline is extracted from columnar cacti, not the vulnerable peyote.[23]](/Images/godic/202501/10/Flowering_San_Pedro_cactus2908.jpg")
A drug is any substance other than food, that when inhaled, injected, smoked, consumed, absorbed via a patch on the skin or dissolved under the tongue causes a physiological change in the body.
In pharmacology, a pharmaceutical drug or medicine, is a chemical substance used to treat, cure, prevent, diagnose a disease or promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a limited duration, or on a regular basis for chronic disorders.