Dimethylglycine is a highly unusual supplement, in that it is extremely popular despite the
fact that all of its touted effects have largely been refuted by clinical and laboratory testing. It
is most widely used as a performance enhancer by athletes and in dogs and horses that are
bred for racing purposes. Specifically, DMG is thought to be able to reduce lactic acid build
up that might otherwise contribute to muscle fatigue. There is no immediately obvious
reason why DMG should be able to achieve this, given its role in the body as a metabolite of
betaine and a source of glycine. Reports of an ability of DMG to enhance athletic
performance first appeared in the popular literature in the 1980’s. Controlled studies
involving treadmill horses, male athletes, and patients prone to lactic acid build up due to a
cytochrome oxidase deficiency fail to support these
earlier claims. Other common uses of DMG which
are refuted by clinical research include the
treatment of autism and idiopathic epilepsy.