Trimethylamine N oxide (TMAO): Pathway, Cardiovascular Risk, Diet & LCMS MS Testing Does Carnitine Cause Body Odor? Lume Deodorant The adverse effects of long term l carnitine supplementation on liver and kidney function in rats L Liu, D M Zhang, M X Wang, C Y Fan, F Zhou, S J Wang, L D Kong, 2015 Do you or someone you love smell like fish? It could be Fish Odor Syndrome! #fishodorsyndrome #fishy #fishysmell #fishodor 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 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.