You are here

Side Effects Of Phenylalanine

sumitaThomas's picture

Aspartame in diet cokeOne of the 9 essential amino acids that the human body needs is phenylalanine. It  is required for many functions that involve the skin, nerves as well as the transport of important substances in the body. Careless supplementation and accidental overdose are the common reasons for side effects of this amino acid. To prevent this, one must learn how to identify food items that are good source of amino acids so that dangerous levels are not ingested. Phenylalanine that is present in dairy, meat, nuts and seeds is available in sufficient quantities from dietary sources. The side effects of this amino acid that are seen on unnecessary supplementation and in some genetic disorders are given below.



Negative Effects Of Phenylalanine Supplementation


  • Drug Interaction- Levadopa is a drug that is commonly prescribed for the treatment of Parkinson's disease. When phenylalanine is taken along with this, it reduces the effectiveness and absorption of levedopa. This makes treatment slow and difficult.


  • Worsening Of Phenylketonuria- This genetic disorder causes the body to retain high levels of phenylalanine which causes brain damage, seizures and retarded mental growth. Along with the use of a low phenylalanine diet, there must be a complete restriction of other sources like the artificial sweetener aspartame and dietary supplements that contain this amino acid.


  • Hyperactivity- The use of this amino acid in the supplement form is known to cause irritability, anxiety and mood changes in children that can affect normal growth and development patterns.


  • Blood Pressure Changes- The use of phenyalanine along with monoamine oxidase inhibitors (MAOIs) which are antidepressants, can lead to extremely high blood pressure resulting in a heart attack and stroke.


  • Adverse Pregnancy Outcomes- Pregnant women should avoid diet sodas as the high phenylalanine content in it can lead to facial, heart and nervous system defects in the fetus which is irreversible. Phenylalanine supplements should be taken only after getting a doctor's approval.


To avoid these side effects one must use the phenylalanine supplements with great caution. It is better to be safe than sorry when one's health is in question. 


Image Credit



Rate This

Your rating: None
Average: 4.8 (4 votes)
Side Effects Of Phenylalanine