Dimethylamylamine (4-methylhexan-2-amine, DMAA) is a stimulant commonly found in athletic training or pre-workout supplements. A number of commercially available products containing DMAA have been marketed as exercise boosters, promoting weight loss, or acting as an appetite inhibitor. DMAA is an aliphatic amine, with structural and pharmacological similarities to other sympathomimetic amines like tuaminoheptane (1-methylhexylamine). DMAA and tuaminoheptane are structural isomers, central nervous system stimulants, and are both included on professional and amateur sports prohibition lists such as the World AntiDoping Agency (WADA).[1–7] DMAA was originally developed in the 1940s by Eli Lilly, who commercially advertised it as the nasal decongestant Forthane.[2,4,8–10] Although Forthane was later removed from the market, DMAA eventually resurfaced as a dietary supplement in the 2000s, not long after the US ban of ephedrine.[9,11–13] For DMAA to qualify as a natural supplement, a single study was used to claim that it originated from geranium extracts, but this study is now widely debunked and no substantive evidence exists that DMAA occurs in nature.[3,14] In fact, in a study by Zhang et al., the presence of DMAA was not established in multiple geranium products, and the stereoisomeric compositions of DMAA in synthetic standards and commercial supplements were indistinguishable, confirming that DMAA cannot be considered a dietary supplement as defined by the Dietary Supplement Health and Education Act.[14] DMAA does not currently have any recognized medical use and the substance is banned or restricted in a number of countries. Since its introduction as a nutritional supplement, DMAA use has been controversial. DMAA was detected in multiple routine athletic drug testing programmes in which it is prohibited, resulting in the athletes being banned from competition,[3,8,9,14] More importantly, DMAA has been implicated as contributing to severe adverse effects and/or death on numerous occasions.[2,15–17] Because the nature of DMAA as a natural supplement is in question, in 2012 the US Food and Drug Administration (FDA) sent letters to supplement companies requesting detailed safety information.[18] Subsequently, supplement manufacturers have begun to change their formulations, advertising, and product labels. However, products containing DMAA are still commonly available in stores and over the Internet, and more recently, DMAA has been found as a component of abused drug formulations, in particular ‘legal high’ designer drug mixtures in the USA.[2,19] Because DMAA was identified as present in multiple non-traumatic deaths in the US military,[15] in early 2012 products containing DMAA were removed from military bases and their use was prohibited pending further testing on their health effects. In early 2013, the FDA issued a warning, listing the substance as dangerous and it is now illegal for military personnel to consume any product that contains DMAA.[20–22] Regardless, due to the association of DMAA with military fatalities, sports doping, and abused drug mixtures, testing by such agencies may need to specifically include it in routine screenings. A common sequence in routine screenings is to perform a rapid, preliminary assay, such as an immunoassay, followed by confirmatory mass spectrometry methods. For example, it is documented that branches of the US military employ three tests to report a positive result in urine screening, including two .....