Researchers have not conclusively determined whether supplementing horses with DMG offers these beneficial impacts. | Photo: Anne M. Eberhardt/The Horse

Q: As I condition my horse for the spring competition season I’m looking at supplements to both support my horse’s muscle development and help performance. I see DMG and creatine are common ingredients in the supplements I am researching. What are these, and do they improve performance?

A: The acronym “DMG” stands for dimethylglycine, which is a derivative of the amino acid glycine and an ergogenic compound, meaning it’s used to improve performance, recovery, or stamina. Sometimes referred to as vitamin B15, DMG contains two methyl groups, which it can donate to various reactions within the body. These include aerobic energy production pathways that use oxygen. A version with three methyl groups exists, trimethylglycine (also known as betaine).

Dimethylglycine occurs naturally in animals and plants and is an intermediary product of choline metabolism (choline is a water-soluble vitamin involved in the metabolism and transport of fats). It’s thought to enhance muscle creatine levels