Oral Vs. Injectable L Carnitine Weight Wise Weight Loss Center Kinetics of carnitine concentration after switching from oral administration to intravenous injection in hemodialysis patients ORAL VS. INJECTABLE L CARNITINE , Does it really matter which you use? , Both have pros and cons but it really comes down to what is going to be most suited to use as an individual athlete., L Carnitine Injection Home Delivered Levocarnitine Oral Solution: Package Insert Prescribing Info Injectable L carnitine works better than oral because it goes straight into your bloodstream, giving almost 100% of absorption versus only 518% with capsules or liquid. Oral L carnitine can take upto 4