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 L Carnitine Pills for Weight Loss: Evidence, Safety and UK Guidance Bolt Pharmacy Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications 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 Effect of dietary fiber on trimethylamine N oxide production after beef consumption and on gut microbiota: MEATMARK a randomized cross over study European Journal of Clinical Nutrition JCI l Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humans