l carnitine iv injection Levocarnitine Injection: Package Insert / Prescribing Info L-Carnitine Inj. (200 Mg./Ml 5
Description
30 minutes before meal or physical exercise.

doi: 10.1111/1567-1364.12196

The one thing to keep in mind is its very short half-life of only ~10-12 minutes

Age-related changes in passive avoidance retention: modulation with dietary choline
doi: 10.1046/j.1600-0404.2003.00227.x