Tyrosine (also known as
L-tyrosine) is a nonessential amino acid. This means that it does not need to be obtained from dietary sources; the human body can make tyrosine using
phenylalanine, another amino acid. Tyrosine is also used in
dietary supplements and is claimed to be useful for a variety of different conditions, such as:
- Depression
- Premenstrual syndrome (PMS)
- Attention deficit hyperactivity disorder (ADHD).
As mentioned, tyrosine is an amino acid that is important for building proteins. For most people, the body can make its own tyrosine, although it is also found in protein-rich foods. People with phenylketonuria (PKU) must obtain tyrosine through the diet, since they cannot produce it. Even though it is a large amino acid, tyrosine can cross the blood-brain barrier to enter the brain, and may have numerous different effects in the brain. It is not known how tyrosine may work for a variety of different disorders.
Tyrosine (as part of a specially designed protein supplement) is effective for people with phenylketonuria, although further supplementation in addition to the protein supplement is usually not recommended. It is not known if tyrosine is effective for other uses.