Tyrosine is one of the 22 amino acids that are used by cells to synthesize proteins. Tyrosine is found in high-protein food products like as chicken, turkey, fish, peanuts, almonds, avocados, milk, cheese, yogurt, cottage cheese, lima beans, pumpkin seeds, sesame seeds, bananas, and soy products.
A number of studies have found tyrosine to be useful during conditions of stress, cold, fatigue, loss of a loved one such as in death or divorce, prolonged work and sleep deprivation with reductions in stress hormone levels reductions in stress-induced weight loss seen in animal trials, improvements in cognitive and physical performance seen in human trials.
Tyrosine is known to help treat phenylketonuria. However, people also take tyrosine for depression, attention deficit disorder (ADD), attention deficit-hyperactivity disorder (ADHD), the inability to stay awake (narcolepsy), and improving alertness following sleep deprivation. It is also used for stress, premenstrual syndrome (PMS), Parkinson’s disease, Alzheimer’s disease, chronic fatigue syndrome (CFS), alcohol and cocaine withdrawal, heart disease and stroke, erectile dysfunction, loss of interest in sex, schizophrenia, and as an appetite suppressant.