Does L carnitine cause fishy body odor? Surprising Truth and Solutions Tonum 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 When a 12 month old boy in Portugal developed an unexpected and persistent smell similar to rotting fish, his parents were unsettled. The child appeared healthy, showed no signs of infection, and behaved normally. Acetyl L Carnitine 500 mg 90 Caps by Klaire Labs SFI Health Fish odour syndrome CMAJ