Using Internet Snapshot Surveys to Enhance Our Understanding of the Availability of the Novel Psychoactive Substance 4-Methylaminorex and 4,4′-Dimethylaminorex

4,4'-Dimethylaminorex is a stimulant novel psychoactive substance (NPS) first detected in Europe in November 2012. It is a derivative of 4-methylaminorex, a substance controlled under Schedule 1 of the 1971 United Nations Convention on Psychotropic Substances. There is currently no information on the availability or cost of these substances from Internet suppliers. An Internet snapshot study was undertaken in English using established European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) methodology to determine the availability of 4-methylaminorex and 4,4'-dimethylaminorex in April 2014. Twenty Internet sites selling 4-methylaminorex were identified, 18 selling in US dollars and two in GB Pound Sterling. Fourteen (70 %) Internet sites had a minimum purchase amount of >= 10 g (compared to user doses of 10-25 mg). For the 18 suppliers selling in US$, 9 quoted a fixed price per gram irrespective of the amount ordered and 11 had a reducing price per gram with increasing purchase quantity (US$30.8 +/- 34.2/g for 1 g purchase to US$15.2 +/- 20.3/g for 1 kg purchase). Only one Internet site selling 4,4'-dimethylaminorex was identified, selling in Euros. The minimum purchase quantity was 500 mg. The price per gram reduced from (sic)36.08/g for a 500 mg purchase to (sic)2.20/g for a 100 g purchase. This Internet snapshot demonstrated that there was a greater availability from Internet suppliers of products advertised as 4-methylaminorex than 4,4'-dimethylaminorex, despite the 4-methylaminorex being an internationally controlled substance. Whilst this may reflect misunderstanding by suppliers, it has the potential to put those purchasing at risk of contravening border control and/or local law enforcement legislation. The use of methodology such as Internet snapshot surveys is of increasing interest to clinical/medical toxicologists in their understanding of the supply, availability and cost of novel psychoactive substances.