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 Why Does L Carnitine Smell Like Fish TikTok Carnitine: the claims and why it may not work Too Much L Carnitine Smell Fishy TikTok Certain bodily odors are signals that something may be wrong with your health. For instance, bad breath or dark stools could indicate a digestive issue or H. Pylori infection. If you experience Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish.