A process in which the body rids itself of a drug, or its metabolites. Medically-assisted detoxification may be needed to help manage a person’s withdrawal symptoms. Detoxification alone is not a treatment for substance use disorders, but this is often the first step in a drug treatment program.

From WHO lexicton: (1) The process by which an individual is withdrawn from the effects of a psychoactive substance. (2) As a clinical procedure, the withdrawal process carried out in a safe and effective manner, such that withdrawal symptoms are minimized. The facility in which this takes place may be variously termed a detoxification centre, detox centre, or sobering-up station.

Typically, the individual is clinically intoxicated or already in withdrawal at the outset of detoxification. Detoxification may or may not involve the administration of medication. When it does, the medication given is usually a drug that shows cross-tolerance and cross-dependence to the substance(s) taken by the patient. The dose is calculated to relieve the withdrawal syndrome without inducing intoxication, and is gradually tapered off as the patient recovers. Detoxification as a clinical procedure implies that the individual is supervised until recovery from intoxication or from the physical withdrawal syndrome is complete. The term "self-detoxification" is sometimes used to denote unassisted recovery from a bout of intoxication or withdrawal symptoms (WHO Lexicon of alcohol and drug terms.)