L-Tyrosine is an amino acid found in wheat germ, oats, dairy products, pork and poultry. It is a precursor for the neurotransmitters epinephrine, norepinephrine, and dopamine, which are all essential for mood, cognitive function and central nervous system function. The most prevalent usage for supplemental L-tyrosine appears to be the enhancement of cognitive function and alertness under conditions of environmental stress such as sleep deprivation, multi-tasking in the workplace, and functioning at high altitudes and/or cold temperatures. It is noteworthy to mention that a high percentage of the studies done on L-tyrosine are conducted by the military looking to enhance focus and attention in their personnel. Clinical trials with L-tyrosine have also been conducted with respect to attention deficit disorder (ADD) with good results. L-Tyrosine is also used by the body to make thyroid hormones as well as melanin, the skin and hair pigment.

L-Tyrosine is ideal for those who are required to work long hours under stressful conditions, those whose lifestyles or work require a high degree of multitasking, those who experience prolonged physical and mental stress, students, and those who have difficulty concentrating such as in ADD.