Many people suffer from some form of depressive disorder, a prolonged period of depression that causes a major disruption in your lifestyle. L-phenylalanine in an essential amino acid required for the synthesis of neurotransmitters in your brain. Some evidence suggests that supplementing with L-phenylalanine may improve the effectiveness of antidepressants. L-phenylalanine is not, however, a substitute for antidepressants or other medication prescribed by your doctor.
L-phenylalanine is an essential amino acid found in large amounts in complete proteins sources such as meat, fish, dairy, eggs, soybeans and the artificial sweetener aspartame. L-phenylalanine is used to make the amino acid L-tyrosine and important neurotransmitters in the brain, including serotonin, dopamine, epinephrine and norepinephrine. Supplements may contain L-phenylalanine, the only form used in animal or plant proteins, D-phenylalanine, a mirror image of L-phenylalanine produced in a lab, or DL-phenylalanine, a mixture of the two forms. Though D-phenylalanine cannot be used to make proteins in your body, your body may be able to use it to produce neurotransmitters.
Though everyone feels depressed from time to time, a depressive disorder does not subside on its own. Though the cause is not known, it is likely that depression is caused by a variety of factors that disrupt normal neurotransmitter signaling. Treatments commonly used for depression include antidepressant medication to improve neurotransmitter levels and therapy. Therapy can aid in changing behaviors, lifestyles or learning to avoid situations that may lead to depressive episodes or make depression worse.
Effectiveness of L-Phenylalanine
Forms of phenylalanine may increase your brain's production of certain neurotransmitters, such as serotonin and norepinephrine, which may have a positive effect when used with antidepressants. A 2005 study in the journal "Neuropsychopharmacology" found that depletion of phenylalanine and tyrosine reduced reward behavior in those who had previously suffered from depression. The University of Maryland Medical Center reports that some studies have reported benefits of phenylalanine but few have been recent or well-controlled.
Do not attempt to use L-phenylalanine for the treatment of depression without the supervision of your doctor. People with phenylketonuria, an inherited inability to process phenylalanine, should not take supplements containing phenylalanine. Phenylalanine supplements may change the effectiveness of antidepressants or other drugs you are currently taking. Work closely with your doctor to find the best treatment regimen for your depression.
- University of Maryland Medical Center: Medical Reference: Complementary Medicine: Phenylalanine
- "Neuropsychopharmacology"; The Subjective and Cognitive Effects of Acute Phenylalanine and Tyrosine Depletion in Patients Recovered from Depression; J.P. Roiser et al.; April 2005
- "The Journal of Neural Transmission"; L-Deprenyl Plus L-Phenylalanine in the Treatment of Depression; W. Birkmayer et al.; 1984