ONLY NATURAL PET Thyroid Support Supplement for Cats Multivitamin with L Carnitine & Lemon Balm Vet L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar Exploring the potential anti thyroid activity of Acetyl L carnitine: Lactoperoxidase inhibition profile, iodine complexation and scavenging power against H2O2. Experimental and theoretical studies ScienceDirect ONLY NATURAL PET Thyroid Support Supplement for Cats Multivitamin with L Carnitine & Lemon Balm Vet If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy.