There are four common types of carnitine supplements:
L-Carnitine
Acetyl-L-Carnitine (ALCAR)
L-Carnitine L-Tartrate (LCLT)
and Propionyl-L-Carnitine (GPLC)
ALCAR and LCLT are the most popular forms of L-carnitine, with the latter being recommended when attempting to increase androgen receptor activity and physical performance output.
While ALCAR is commonly referred to as a fat burner, studies do not appear to be promising to that effect. Rather, ALCAR can be used as a stimulant, which then helps people become more active due to supplementation. ALCAR is effective at:
Neurological decline
Improving insulin sensitivity
Chronic fatigue
Cognitive enhancement
How Much L-Carnitine to Take
ALCAR is typically consumed in 600-2,500 mg doses on a daily basis. LCLT is typically consumed at higher daily doses, from 1,000-4,000 mg and should be taken with food.