L-tyrosine is one form of the amino acid tyrosine found in the diet that is metabolized to produce catecholamines such as dopamine and norepinephrine. L-tyrosine is also used in the production of thyroid hormones. L-Tyrosine is commonly taken as a supplement to help increase catecholamine levels depleted during stressful or challenging conditions. It is taken as a free-form amino acid supplement, commonly alone or as part of weight loss or preworkout supplements.

Most people do not need to take L-tyrosine because their bodies have a mechanism for regulating tyrosine supply. If you do not consume sufficiently tyrosine from food, your body can make more. If you consume too much, your body will break it down and get rid of it.

Benefits

Although most people do not need to take L-tyrosine, it may be beneficial in certain circumstances, including these:

• For a few people, tyrosine is an essential amino acid. These are people who have phenylketonuria (PKU). PKU is a serious condition in which phenylalanine builds up in the body. The main treatment for PKU is restricting dietary sources of phenylalanine. Treatment might also include the use of L-tyrosine as a supplement.

• Treatment with tyrosine may help humans perform in stressful situations, such as being exposed to extreme weather or being asked to perform certain cognitive tasks. In several studies, those taking tyrosine did not exhibit the processing problems or the memory deficits that would naturally occur in difficult situations.

• Because tyrosine is turned into the brain chemicals dopamine and norepinephrine, it may play a role in relieving depression. An analysis of several studies found that tyrosine might be effective in treating mild-to-moderate depression.