The difference between L Carnitine and Acetyl L Carnitine (ALCAR) Health4All Most people talk about carnitine like it is one supplement. It is not. Acetyl L carnitine and L carnitine L tartrate do different jobs, and picking the wrong one for the wrong goal is where people Most people talk about carnitine like it is one supplement. It is not. Acetyl L carnitine and L carnitine L tartrate do different jobs, and picking the wrong one for the wrong goal is where people L Carnitine vs Acetyl L Carnitine: Key Differences Acetyl L Carnitine: Benefits, Forms, Dosing, and Side Effects Dr Brad Stanfield