Trimethylglycine (also commonly known as TMG), is an organic compoun described by the formula (CH3)3N+CH2CO2H. Trimethylglycine was originally named betaine after its discovery in sugar beets (Beta vulgaris) in the 19th century. This small N-trimethylated amino acid exists as the zwitterion (CH3)3N+CH2CO2- at neutral pH. This substance is often called ‘‘glycine betaine’’ to distinguish it from other betaines that are widely distributed in biology. Betaine hydrochloride is merely glycine betaine with a chloride counterion and is usually the first crystallised form obtained after extraction from beets. Glycine betaine is a byproduct of the sugar industry.