What is phenylalanine?

Phenylalanine is an essential amino acid for humans. It comes in three different forms: L-phenylalanine, which is what is found in natural sources of this amino acid; D-phenylalanine, which is a synthesized version from a lab; and DL-phenylalanine, which combines the prior two forms.

Many people receive sufficient amounts of phenylalanine from their diet. However, in some situations, such as with some vegetarians, adequate amounts are not naturally ingested. In such a circumstance, phenylalanine supplements may be recommended.


Phenylalanine is considered to have the potential or possibility to be beneficial for patients in several ways, and some of these may include:

Analgesic (painkiller)
Appetite suppression
Attention deficit disorder
Chronic pain in certain health conditions
Parkinson's disease (including related depression)
Premenstrual syndrome (PMS)
Speech difficulties
Vitiligo (combining oral and topical forms with UVA radiation)
Walking disabilities and improved rigidity

Side Effects

Phenylalanine can be toxic in large doses, generally in excess of 5,000 mg in a day. Nerve damage can be caused by excessive phenylalanine intake, even up to irreversible brain damage and eventually death. This can happen when high quantities of phenylalanine are taken, or during pregnancy.

Large amounts of the DL-phenylalanine form may lead to relatively mild side effects, for instance: headaches, heartburn, and nausea.

Individuals with phenylketonuria (PKU) are unable to properly metabolize phenylalanine due to a missing enzyme. These individuals, phenylketonurics, are to avoid large amounts of phenylalanine. Hyperphenylalanine, a separate condition, is a state in which some pregnant women are unable to properly metabolize it, and blood levels of phenylalanine become elevated. Women with this condition are also to avoid extra intake of phenylalanine.

Natural Sources

Phenylalanine is found in a variety of natural sources. The following are several:

Nuts (some)
Poultry (chicken, etc.)
Seeds (some)
Soy products

Aspartame, an artificial sweetener, is a frequent non-natural source of phenylalanine.

To continue reading about phenylalanine, including symptoms of a deficiency, as well as other topics, please visit this site particularly about phenylalanine.

Copyright 2009-2015 Mijiki.com -- Terms and Conditions || Privacy Policy