DL-phenylalanine (DLPA) is a combination of the essential amino acid L-phenylalanine and the additional stereoisomer D-phenylalanine. These chemicals have been shown to have an effect on mood. They are shown to elevate mood and can thus be used in the treatment of depression. DL-phenylalanine supplements may also increase the ability to concentrate.
L-phenylalanine is an important precursor in the creation of many of the neurotransmitters used within the brain. L-phenylalanine is converted within the body into L-tyrosine, another important amino acid. It is used in the creation of L-dihydroxyphenylalanine (L-DOPA), which is then converted into dopamine.
The brain uses dopamine for a large number of functions. Dopamine is directly linked to the ability of an individual to concentrate, process information, and recognize patterns. Dopamine also is associated with feelings of sexual gratification. Memory and learning are also affected by dopamine.
DL-phenylalanine helps to boost the levels of this important neurotransmitter. Dopamine itself is then converted into norepinephrine. Norepinephrine is another neurotransmitter that has an affect on the ability of individuals to concentrate; it also aids memory. It helps to regulate blood pressure by acting on the alpha receptors within the brain. This causes the blood vessels within the body to constrict, raising blood pressure.
As a precursor to these important neurotransmitters, DL-phenylalanine supplements are able to boost the levels of the neurotransmitters in the brain. This can be useful for individuals suffering from depression, as dopamine and norepinephrine levels are thought to have an antidepressant effect in many individuals. The increase of these chemicals also results in an increase in focus which may make it useful for individuals with attention deficit hyperactivity disorder (ADHD).
The D-phenylalanine within DL-phenylalanine supplements is absorbed through the small intestine. Some of this D-phenylalanine is then converted by the body into L-phenylalanine. D-phenylalanine is less able to pass through the blood-brain barrier than its counterpart L-phenylalanine, which results in some of the D-phenylalanine being excreted in urine.
There is a genetic disorder known as phenylketonuria (PKU) that results in an individual being unable to metabolize phenylalanine. These individuals must regulate the intake of phenylalanine in their system and therefore should not take DL-phenylalanine supplements. Pregnant women may experience a condition known as hyperphenylalaninemia and may have high phenylalanine levels within their blood. This condition may be dangerous, but it will often resolve itself after birth.