Acetyl L carnitine is a white crystalline solid that resembles snow. It has a mild odor similar to vinegar. It is a metabolite of L carnitine, derived from the amino acid L lysine in a series Trimethylamine N Oxide in Aquatic Foods Journal of Agricultural and Food Chemistry l Carnitine and its attributed functions in fish culture and nutritiona review ScienceDirect Stabilizing the enzyme in fish odor syndrome Trimethylaminuria (Fish Odor Syndrome or TMAU) Emerging role of trimethylamine N oxide (TMAO) in colorectal cancer Applied Microbiology and Biotechnology Springer Nature Link