What is Trimethylglycine (TMG)? BULK POWDERS™ Trimethylglycine is 100% pure & offers great value for your money, from only 8p per serving! Trimethylglycine, commonly abbreviated to TMG, is a trimethyl derivate of the amino acid Glycine. BULK POWDERS™ are one of few companies to offer pure Trimethylglycine. Trimethylglycine is naturally occurring & can be found in animals, plants & microorganisms. Examples of dietary sources include seafood, wheat-germ, spinach & quinoa. Benefits