Customer reviews for Nutricost L Carnitine Tartrate Supplement Powder (100 Grams) 1 Gram per Serving; 100 Servings Walmart.com Trimethylaminuria, or fish odour syndrome is an uncommon condition that causes an unpleasant, fishy smell. The body is unable to turn a strong smelling chemical called trimethylamine produced in the gut when The Right Way to Take L Carnitine to Boost Your Training 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