L-Tyrosine is an essential amino acid and a precursor of the neurotransmitters dopamine, norepinephrine, epinephrine (adrenaline) and the thyroid hormones.
L-tyrosine aids in the functions of the adrenal, thyroid and pituitary glands. It is converted into thyroid hormone, or thyroxin, which plays an important role in controlling metabolic rate, skin health, mental health, and growth rate. Tyrosine is specifically used to treat depression because it is a precursor for those neurotransmitters that are responsible for transmitting nerve impulses and essential for preventing depression.
Amino acids are the 20 building blocks of protein. Some amino acids are essential, and others are non-essential. Essential means that your body cannot produce them and so you must get them from your diet. Non-essential amino acids can be produced by your body from the essential amino acids.
L-Tyrosine is a non-essential amino acid for most people, because your body can produce it from phenylalanine. (Some people have a genetic disease called phenylketonuria, or PKU, which prevents their bodies from converting phenylalanine into tyrosine.)
Amino acids come in two forms, L- and D-, which are mirror images of each other. The L- form is found in food, and is generally the form used in our bodies.
Although tyrosine can be produced in our bodies, the question is whether you have enough tyrosine in your body to produce sufficient quantities of neurotransmitters.
