Detox, short for detoxification, in general is the removal of toxic substances from the body. In conventional medicine, detoxification can also be achieved artificially by techniques such as dialysis and (in a very limited number of cases) chelation therapy. There is a firm scientific base in evidence-based medicine for this type of detoxification. Many alternative medicine practitioners promote various other types of detoxification such as "diet detoxification" but there's no evidence that detox diets have any health benefits.

Detoxification can also refer to the period of withdrawal during which a person's body to return to homeostasis after long-term use of an addictive substance.
Certain approaches in alternative medicine claim to remove toxins from the body through herbal, electrical or electromagnetic treatments (such as the Aqua Detox treatment). These toxins are undefined and have little scientific basis, making the validity of such techniques questionable. There is no evidence for toxic accumulation in these cases, as the liver and kidneys automatically detoxify and excrete many toxic materials including metabolic wastes. Under this theory if toxins are too rapidly released without being safely eliminated (such as burning fat that stores toxins) they can damage the body and cause malaise.

Certain diets have an underlying assumption that the body accumulates toxins that must be removed, especially after periods of over-eating or the consumption of non-nutritious and processed foods. As with alternative medicine, the 'toxins' removed are undefined and are ascribed to foods, the environment and the body's own wastes.