What Are the Benefits of DL-Phenylalanine?

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Amino acids are nutrients that make up protein, and phenylalanine is an amino acid. L-phenylalanine is the natural form found in protein-rich foods. D-phenylalanine is the synthetic mirror image. Since some benefits are associated with one form and not the other and vice versa, a third form, DL-phenylalanine is available. DL-phenylalanine is a combination of both forms, which can maximize benefits. It is important to consult your doctor before taking DL-phenylalanine.

Chronic Pain

When pain persists for weeks or months, it is called chronic pain. It may begin with an initial incident such as an injury or infection. DL-phenylalanine appears to improve chronic pain symptoms through up-regulation of your endogenous analgesia system, according to a review published in the October, 2000 journal "Medical Hypothesis." Your EAS is a neural system that suppresses nerve transmissions in your pain pathways. Thus, the EAS is responsible for reducing pain sensations.


Depression is described as a low mood lasting several weeks or longer. Brain chemicals called neurotransmitters play an important role in mood health, and phenylalanine is needed to produce certain neurotransmitters, including dopamine and serotonin. These chemicals influence appetite, energy levels, sleep cycles and mood. When combined with traditional medical care, DL-phenylalanine may help improve depressive symptoms, according to the University of Maryland Medical Center. However, more clinical research is needed.


DL-phenylalanine is available in capsule form and as a topical cream. DL-phenylalanine contains a 50 percent blend of each form. The typical recommended dose for adults is 14 mg per kg of body weight, according to UMMC. The most common range is 750 to 3,000 mg daily. Studies have shown highest efficacy for depression utilized doses of 50 to 200 mg per day.


DL-phenylalanine may be beneficial for certain conditions, but side effects are possible. DL-phenylalanine side effects include nausea, headaches and heartburn. DL-phenylalanine can worsen tardive dyskinesia -- involuntary movements -- if you are currently taking anti-psychotic medication. You should not take DL-phenylalanine if you are on anti-psychotic medication. DL-phenylalanine may interact with a class of antidepressants known as monoamine oxidase inhibitors. Take DL-phenylalanine only after talking to your doctor.