[citation needed]: 95–96 Patrick Arnold reintroduced methylhexanamine in 2006 as a dietary supplement,[14][15] after the final ban of ephedrine in the United States in 2005.

Most studies have been done on pharmacological effects when the drug is inhaled; the understanding of what methylhexanamine does when taken orally are mostly based on extrapolating from the activities of similar compounds.

[20][23][24] Methylhexanamine may be quantified in blood, plasma, or urine by gas or liquid chromatography-mass spectrometry to confirm a diagnosis of poisoning in hospitalized patients or to provide evidence in a medicolegal death investigation.

Blood or plasma methylhexanamine concentrations are expected to be in a range of 10–100 μg/L in persons using the drug recreationally, >100 μg/L in intoxicated patients, and >300 μg/L in victims of acute overdosage.

[29] A 2012 review by a panel convened by the U.S. Department of Defense to study whether the military should ban methylhexanamine supplements from stores on its bases concluded that: "The existing evidence does not conclusively establish that DMAA-containing substances are causally-associated with adverse medical events.

Data from the case control study suggest that the frequency and amount of DMAA use and risk of specific [acquired medical events], particularly heat injuries and rhabdomyolysis, need to be examined in greater detail.

[30] Health authorities in Hawaii linked cases of liver failure and one death to OxyElite Pro, a weight loss and bodybuilding dietary supplement.

[34] A number of sporting authorities and countries have banned or heavily restricted the use of methylhexanamine as a dietary supplement, due to serious concerns about its safety.

Many professional and amateur sports bodies, such as the World Anti Doping Agency, have banned methylhexanamine as a performance-enhancing substance and suspended athletes that have used it.

[62] In June 2012, the National Food Agency of Sweden issued a general warning regarding use of methylhexanamine products, resulting in a sales ban in parts of the country.

[63] In July 2012, the National Health Surveillance Agency of Brazil issued a warning to the general public on the hazards of products that contain methylhexanamine.

[67] In 2012 the New Zealand Ministry of Health banned the sale of methylhexanamine products,[68] due in part to its growing recreational use as party pills.