Frontiers Targeting Trimethylamine N Oxide: A New Therapeutic Strategy for Alleviating Atherosclerosis A 2016 study suggested L carnitine could drop a key cardiovascular risk marker by up to 12%, which sounded promising at first., But follow up research told a more complicated story, with inconsistent Gut microbiota metabolism of l carnitine and cardiovascular risk Atherosclerosis L Carnitine intake and high trimethylamine N oxide plasma levels correlate with low aortic lesions in ApoE transgenic mice expressing CETP Atherosclerosis New study links L carnitine in red meat to heart disease Harvard Health