A non-essential amino acid, L-tyrosine helps your body manufacture several important neurotransmitters that regulate your mood. These include dopamine, the “feel-good” brain chemical associated with pleasure, and epinephrine and norepinephrine, hormones that control the body’s stress response. L-tyrosine is found in a wide variety of foods, so deficiency is rare. But some research suggests that the body cannot make enough L-tyrosine when it is under extreme stress, reports the University of Maryland Medical Center.
Clinical Uses for L-Tyrosine
Several clinical studies have linked L-tyrosine with relief from symptoms of physical or environmental stress, such as intense cold or heat. In a study of military cadets, published in “Brain Research Bulletin” in 1999, those who supplemented with 2 grams of L-tyrosine for five days showed better memory and cognitive performance in a stressful physical training program than those who did not. Studies of L-tyrosine and depression have been less conclusive. A review published in “Alternative Medicine Review” in 2000 looked at numerous older studies and found L-tyrosine only possibly helpful for milder forms of depression.
Food Sources and Dosage
L-tyrosine is found in an array of healthy foods, including poultry, soy, avocados, bananas, almonds, pumpkin seeds, cottage cheese and yogurt. For supplementing with L-tyrosine, Hyla Cass, author of "Natural Highs," suggests 500 to 1,000 milligrams daily on an empty stomach in the morning. She warns that it can cause anxiety and insomnia in some people, and that those with a history of mental illness should never take L-tyrosine supplements.
- University of Maryland Medical Center: Tyrosine
- Journal of Psychiatry & Neuroscience: L-Tyrosine to Alleviate the Effects of Stress?
- Natural Highs; Hyla Cass, M.D., and Patrick Holford
- Brain Research Bulletin: Tyrosine Improves Cognitive Performance and Reduces Blood Pressure in Cadets after One Week of a Combat Training Course
- Alternative Medicine Review: Use of Neurotransmitter Precursors for Treatment of Depression