What Is Dl Phenylalanine Used For?

Amino acids are nitrogen-containing molecules that your body employs for a variety of purposes. Their principal use is in the manufacture of proteins, which serve as structural elements, hormones, antibodies, enzymes, transport molecules and other functional compounds. Your cells can use amino acids to produce energy, and some amino acids can be converted to other amino acids to fulfill specific needs. Among their more obscure roles, some amino acids, such as phenylalanine, are needed to synthesize neurotransmitters that stabilize your moods and reduce pain perception. Ask your doctor if phenylalanine supplements are appropriate for you.

D or L

Amino acids are categorized as D or L forms, depending on which direction they rotate polarized light. D-amino acids rotate light in a clockwise direction, while L-amino acids rotate it counterclockwise. According to nutritionist Elson Haas, M.D., most biological processes require L-amino acids. Only two amino acids -- serine and aspartic acid -- occur naturally in your body in both D and L forms. Your cells can convert many D-amino acids, including D-phenylalanine, to their L forms.

Phenylalanine

Of the 22 naturally occurring amino acids, your body uses 20 to build the proteins it needs and uses the others for non-protein purposes. Scientists at the University of Arizona report that your cells can manufacture 10 of the amino acids you require, while the remainder -- the "essential" amino acids -- must be obtained from your diet. L-phenylalanine is an essential amino acid. It is utilized for constructing a number of proteins, and it is converted to L-tyrosine, which is the precursor for important chemical messengers in your nervous system.

Chemical Messengers

As the precursor for L-tyrosine, L-phenylalanine helps maintain levels of several important chemical messengers in your body. L-phenylalanine -- which can be derived from D- or DL-phenylalanine -- is converted to L-tyrosine, which is in turn converted to dopamine, epinephrine and norepinephrine. These neurotransmitters help to regulate your moods, alertness, responsiveness and energy levels. L-phenylalanine is also incorporated into endorphins and enkephalins, which are neurohormones that play a role in your response to pain.

Uses

Because they can all be converted to dopamine and other catecholamine neurotransmitters, D-, L- and DL-phenylalanine have been used to treat depression and bipolar disorders. Depending on your personal biochemistry, one form or the other might prove more effective, but D- and DL-phenylalanine are reputed to work better on depression, while L-phenylalanine is better for bipolar disorder. DL-phenylalanine is also useful for managing chronic pain conditions, such as fibromyalgia or back pain. A 1989 study performed at Harvard University in Cambridge, Massachusetts, demonstrated that D-phenylalanine blocks the enzyme that breaks down endorphins and enkephalins, thereby increasing your brain levels of these pain-modulating chemicals.

Considerations and Dosages

DL-phenylalanine, a mixture of D- and L-phenylalanine, is used as an alternative treatment for depression, bipolar disorder and chronic pain. Because these disorders are influenced by a number of factors, supplementation with DL-phenylalanine might not work for you. Dosages for all conditions are the same. Start with 500 mg once or twice daily and gradually increase to 3 g daily in divided doses. Take 50 to 100 mg of vitamin B-6 twice daily to improve phenylalanine metabolism. As with all alternative remedies, consult with a medical professional before taking DL-phenylalanine.