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 L Carnitine Fumarate, 180 Veggie Caps (500 mg per Veggie Cap) Altered carnitine acylcarnitine profiles in levothyroxine treated congenital hypothyroid patients with fatigue: An LC MS MS based study from Bangladesh PLOS One PDF) Adding L Carnitine and Selenium to Methimazole in Graves' Disease: A Prospective Randomized Trial on Thyroid Markers and Quality of Life