Mental Focus Caffeine, Alc & Tyrosine MENTAL FOCUS is based on an ingredient matrix providing stimulant Caffeine, Acetyl L-Carnitine (ALC) and the amino acid Tyrosine popular in energy drinks. Caffeine is well-known to contribute to mental alertness, concentration, and it can increase performance during exercise. Acetyl L-Carnitine (ALC) is the acetylated form of L-Carnitine that has slightly different characteristics and it’s one of the most popular Carnitine analogues. During strenuous exercise a large portion of L-Carnitine is converted to ALC inside the mitochondria by the Carnitine O-Acetyltransferase enzyme.