L Carnitine is often marketed as a fat burner, but most people dont realize that oral and injectable L Carnitine are not the same..Oral L Carnitine has poor absorption (only 20% bioavailability), CARNITOR (levocarnitine) Injection 1 g per 5 mL vial For Intravenous Use Only. L Carnitine Dosage for Erectile Dysfunction: What the Evidence Shows and How to Use It Safely PDF) Effects of switching from oral administration to intravenous injection of L carnitine on lipid metabolism in hemodialysis patients