Phenylalanine

18/Description

About

Phenylalanine is an amino acid, a "building block" of protein. There are three forms of phenylalanine: D-phenylalanine, L-phenylalanine, and the mix made in the laboratory called DL-phenylalanine. D-phenylalanine is not an essential amino acid, and its role in people is not currently understood. L-phenylalanine is an essential amino acid and is the only form of phenylalanine found in proteins. Major dietary sources of L-phenylalanine include meat, fish, eggs, cheese, and milk.

Phenylalanine is used for depression, attention deficit-hyperactivity disorder (ADHD), Parkinson's disease, chronic pain, osteoarthritis, rheumatoid arthritis, alcohol withdrawal symptoms, and a skin disease called vitiligo.

Some people apply it directly to the skin for vitiligo.

How it works

The body uses phenylalanine to make chemical messengers, but it is not clear how phenylalanine might work.

Effectiveness

Possibly Effective
A skin condition called vitiligo

Taking L-phenylalanine by mouth in combination with UVA exposure or applying L-phenylalanine to the skin in combination with UVA exposure seems to be effective for treating vitiligo in adults and in children.

Concerns

Likely safe

L-phenylalanine is LIKELY SAFE for most people when consumed in amounts commonly found in foods

Possibly safe

Phenylalanine is POSSIBLY SAFE when taken by mouth as medicine.There is not enough reliable information available about the safety of D-phenylalanine.

18/Warnings

Warnings

Pregnancy and breast-feeding: Phenylalanine isLIKELY SAFEwhen consumed in amounts commonly found in foods bypregnantwomen who have normal phenylalanine levels. However, having too much phenylalanine in themother's system duringpregnancycan increase the chances of birth defects. The risk for facial defects is highest at weeks 10-14, nervous system and growth defects between 3-16 weeks, andheartdefects at 3-8 weeks. For women whoprocessphenylalanine normally and have normal levels, it is probably fine to get the amount of phenylalanine found infood, but not in higher doses. Do not take supplements. For women who have high levels of phenylalanine, even normal food amounts areUNSAFE. Additionally, experts recommend a low phenylalanine diet for at least 20 weeks before getting pregnant. This should reduce the risk of birth defects.

Phenylalanine is LIKELY SAFE for breast-feeding mothers whose bodies' process phenylalanine normally to consume the amount of phenylalanine found in food. However, do not take more. Not enough is known about the safety of taking phenylalanine in medicinal amounts during breast-feeding.

Phenylketonuria (PKU) and other conditions that cause high levels of phenylalanine: Phenylalanine should be avoided in people with certain inherited disorders that cause their bodies to build up too much phenylalanine. Phenylketonuria (PKU) is one of these diseases. People with this disorder can develop mental retardation, high blood pressure, stroke, and many other serious health issues if they consume phenylalanine. PKU is so serious that babies are screened at birth to determine whether they have the disorder and will need a special diet to avoid these problems.

Schizophrenia: Use with caution. Phenylalanine can make a movement disorder (tardive dyskinesia) in people with schizophrenia worse.

Interactions

Always consult with your doctor.
Major
Levodopa

Levodopa is used for Parkinson's disease. Taking phenylalanine along with levodopa can make Parkinson's disease worse. Do not take phenylalanine if you are taking levodopa.

Moderate
Baclofen

Phenylalanine might decrease how much baclofen the body absorbs. Be cautious when taking this combination.

Medications for mental conditions (Antipsychotic drugs)

Phenylalanine can increase a chemical in the body called tyramine. Large amounts of tyramine can cause high blood pressure. But the body naturally breaks down tyramine to get rid of it. This usually prevents the tyramine from causing high blood pressure. Some medications used for depression stop the body from breaking down tyramine. This can cause there to be too much tyramine and lead to dangerously high blood pressure.Some of these medications used for depression include phenelzine (Nardil), tranylcypromine (Parnate), and others.Some medications for mental conditions might cause jerky muscle movements. Taking phenylalanine along with some medications for mental conditions might increase the risk of jerky muscle movements.Some medications for mental conditions include chlorpromazine (Thorazine), clozapine (Clozaril), fluphenazine (Prolixin), haloperidol (Haldol), olanzapine (Zyprexa), perphenazine (Trilafon), prochlorperazine (Compazine), quetiapine (Seroquel), risperidone (Risperdal), thioridazine (Mellaril), thiothixene (Navane), and others.

The information provided on this page is for reference purposes and is not meant to be used as a medical advice, diagnosis or treatment. Always consult with a medical professional. The content on this page has been provided with thanks by RxList.com