Oxyenergys L Carnitine. My go to pre post workout supplement. Pre workout I usually take it before my workout session for energy production. Post workout Ill take it the day after my workout Altered carnitine acylcarnitine profiles in levothyroxine treated congenital hypothyroid patients with fatigue: An LC MS MS based study from Bangladesh PLOS One L Carnitine Fumarate, 180 Veggie Caps (500 mg per Veggie Cap) Amazon.com : ONLY NATURAL PET Thyroid Support Supplement for Cats Multivitamin with L Carnitine & Lemon Balm Vet Formulated Helps with Endocrine & Immune Health Turkey Flavored Chewable 90 Tablets : Pet Supplies PDF) Adding L Carnitine and Selenium to Methimazole in Graves' Disease: A Prospective Randomized Trial on Thyroid Markers and Quality of Life