Tyrosine is a non-essential amino acid required for optimal functioning of numerous biochemical pathways and physiological processes. It is a building block for thyroid hormone and the neurotransmitters dopamine, epinephrine and norepinephrine. As such, adequate intake of tyrosine is important for supporting steady energy levels, an efficient metabolic rate, a positive mental outlook, and a healthy response to stress.
Even though the body can synthesize tyrosine internally, the capacity for this declines with age, and many health conditions may increase the need for tyrosine above that which is typically obtained through the diet. Moreover, other amino acids compete with tyrosine for absorption, so in order to effectively optimize tyrosine levels in the body, some individuals may benefit from taking supplemental tyrosine separately from other protein-rich foods.