Learn More About L-Tyrosine
What is l-tyrosine?
L-tyrosine, or tyrosine, is a nonessential amino acid. This means that it can be synthesized by the body from phenylalanine. Tyrosine plays an important role in the thyroid, nervous system, and skin.
What are the benefits of l-tyrosine?
Tyrosine is an important input in the production of neurotransmitters; most notably dopamine and norepinephrine.
The amino acid L-tyrosine can be converted into norepinephrine, a neurotransmitter that affects mood. Women taking oral contraceptives have lower levels of tyrosine, and some researchers think this might be related to depression caused by birth control pills. L-tyrosine metabolism may also be abnormal in other depressed people and preliminary research suggests supplementation might help. Several doctors recommend a 12-week trial of L-tyrosine supplementation for people who are depressed. Published research has used a very high amount—100 mg per 2.2 pounds of body weight (or about 7 grams per day for an average adult). It is not known whether such high amounts are necessary to produce an antidepressant effect.1
Because of its role in the synthesis of neurotransmitters, tyrosine is thought to be beneficial for people suffering from mood disorders, Parkinson’s, Alzheimer’s, and depression. Several case studies were performed on patients with Alzheimer's. The patients were started out with low doses of 5-HTP, tyrosine, levodopa, and cysteine. The dosage was slowly increased, and over a period of just a few weeks the patients showed dramatic improvement in quality of life and cognitive abilities.
Further studies have shown tyrosine to be beneficial during prolonged stress, cold, fatigue, prolonged sleep depravation. Its benefits come in the form of reduced stress hormone levels. Tyrosine has also been attributed with increases in cognitive and physical performance.
Tyrosine attaches to iodine molecules and is essential for the production of certain thyroid hormones. Low levels of tyrosine have been noted in people suffering from hypothyroidism. Impaired thyroid function has also been associated with depression.
Skin cells convert l-tyrosine into melatonin,the component in skin that absorbs harmful ultraviolet rays.
How much l-tyrosine is usually taken?
The average diet provides approximately 500mgs to 1500mgs of tyrosine daily. Amounts administered in the above mentioned studies were approximately 7 grams per day for an adult weighing 150 lbs.
Who is deficient is l-tyrosine?
People affected with Phenylketonuria are usually deficient in tyrosine.Phenylketonuria is a rare genetic disorder in which high amounts of the amino acid phenylalanine exist in the blood. These elevated levels reduce the levels of l-tyrosine in the blood. Persons affected with depression and some kidney diseases may also be deficient in tyrosine.