Acetyl L-Carnitine (ALCAR) is an acetylated form of L-Carnitine which is similar to typical L-Carnitine but is able to cross the blood-brain barrier. L-Carnitine is a compound naturally produced by the body which plays a key role in the mitochondrial oxidation of long-chain fatty acids. When taken as a supplement, ALCAR supports exercise endurance and stamina, particularly for resistance training. Since ALCAR can cross the blood brain barrier, unlike the non-acetylated L-Carnitine it supports cognitive function and attention.