L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications Carnitine and Thyroid Disease page 1 Life Extension Graves' Disease and the Manifestations of Thyrotoxicosis Endotext NCBI Bookshelf