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 Frontiers Role of Carnitine in Non alcoholic Fatty Liver Disease and Other Related Diseases: An Update L Carnitine Benefits for Male Erectile Dysfunction L Carnitine and Erectile Dysfunction: What the Evidence Shows for Everyday Use Acetyl L Carnitine for Erectile Dysfunction: What the Evidence Shows and How to Use It Practically