L-Tyrosine

L-Tyrosine is an amino acid found in the diet that is metabolized to produce catecholamines such as dopamine and adrenaline. It is also used in the production of thyroid hormones. L-Tyrosine increases dopamine and adrenaline. The synthesis of catecholamines is highly regulated in the body, so simply increasing the amount of L-tyrosine in your body does not necessarily increase catecholamine production.

The main effects of L-tyrosine that have been reported are acute effects in preventing a decline in cognitive function in response to physical stress. The physical stressors include those of interest to the military, such as cold stress, the combination of cold stress and high-altitude stress (i.e., mild hypoxia), extended wakefulness and lower body negative pressure stress (designed to simulate some of the effects of space flight).