What is it?

One amino acid that has not gotten a great deal of attention by athletes is the amino acid L- Tyrosine. L- Tyrosine is found in high amounts in protein foods and the body can make L- Tyrosine from amino acid phenylalanine, technically making it a “non-essential” amino acid.

What is it supposed to do?

This often overlooked amino acid plays many important roles in human metabolism. L- Tyrosine is a precursor or “building block” to the neurotransmitters responsible for maintaining metabolic rate. L- Tyrosine is the direct precursor to stimulatory neurotransmitters such as epinephrine and norepinephrine (i.e. adrenaline) as well as certain thyroid hormones and dopamine.

Due to the fact that Tyrosine is essential to the production of all the above stimulatory hormones and neurotransmitters, some consider it an amino acid with mild stimulant-like properties to the metabolism and mental focus.

Some weight loss supplements contain L- Tyrosine in an attempt to supply this essential building block in hopes it will help maintain a higher metabolism.

What does the real world have to say?

It’s not uncommon that people are given advice on what to eat in regards to the food’s amino acid content. For example, many people have probably heard at one time or another, “If you want to be more alert, eat a high protein food.” This advice is probably due to the high l- tyrosine content of the food. Conversely, people are also given advice that to relax, they should eat foods such as milk and turkey, which are high in the amino acid l-tryptophan.

L-Tryptophan is a building block of the neurotransmitter serotonin, which is known to help with sleep and relaxation. Some strength athletes have found that by taking 500 to 2000 mg of tyrosine prior to exercise, they have more energy, but no studies to date have
found this to be an eff ect of tyrosine.

However, because it may be a mild stimulant and works at the level of the central nervous system, people using MAO inhibitors, pregnant women, people with high blood pressure and people sensitive to stimulants, should probably avoid high doses of tyrosine.