L Carnitine Benefits: A Complete Research Based Guide 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 L Carnitine Linus Pauling Institute Oregon State University Vaginal epithelial dysfunction is mediated by the microbiome, metabolome, and mTOR signaling: Cell Reports