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 L carnitine supplements can cause a fishy odor in the breath, sweat, and urine. This is likely due to the formation of trimethylamine (TMA). TMA is also responsible for the pungent smell of Nature's Truth L Carnitine 1000mg 60 Capsules : Target Liquid L Carnitine Citrus iSatori Liquid L Carnitine LS3 3000