L carnitine is primarily synthesized in the liver from the amino acids lysine and methionine through a series of four enzymatic reactions, with the liver and kidneys converting the precursor butyrobetaine into active TMAO: The Gut Metabolite Linking Red Meat to Cardiovascular Disease Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications L Carnitine with Chromium Wycoff Wellness