2-Methylimidazole-d3 is the isotope labelled analog of 2-Methylimidazole (M312985); a monomethylated imidazole that can be used as a building block in the preparation of a wide range of biologically active compounds. 2-Methylimidazole as well as other imidazoles can be use as catalyst for refolding of enhanced coloured fluorescent protein. 2-Methylimidazole has been identified as a byproduct of fermentation and is detected in foods and mainstream and side-stream tobacco smoke.