Which is better creatine or L carnitine? Kintai L Carnitine Injection VolusiaMedicalCenter L Carnitine Injection Levocarnitine IV Injectable L carnitine vs oral? For me, absorption, fewer GI issues, & energy performance gains make injections the winner. #LCarnitine #Injectable #Bioavailability #MetabolicHealth #EnergyBoost 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),