Trimethylaminuria (Fish Odor Syndrome or TMAU) Amazon.com: Nutricost Acetyl L Carnitine (ALCAR) 500mg, 180 Capsules, 180 Servings Non GMO and Gluten Free, 1 Capsule per Serving : Everything Else Supplements & Body Odor ConsumerLab.com 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 Optimizing endurance performance in elite swimmers: effects of L carnitine supplementation and hydration strategies Applied Water Science Springer Nature Link