Scientists and health organizations have criticized the concept of detoxification for its unsound scientific basis and for the lack of evidence for claims made. The "toxins" usually remain undefined, with little to no evidence of toxic accumulation in the patient. The British organisation Sense About Science has described some detox diets and commercial products as "a waste of time and money", while the British Dietetic Association called the idea "nonsense" and a "marketing myth". Dara Mohammadi summarizes "detoxing" as "a scam [...] a pseudo-medical concept designed to sell you things", and Edzard Ernst, emeritus professor of complementary medicine, describes it as a term for conventional medical treatments for addiction which has been "hijacked by entrepreneurs, quacks and charlatans to sell a bogus treatment".