Equip yourself. Learn about phenylalanine.

Phenylalanine deficiency

Although most people receive sufficient phenylalanine through dietary sources, in some cases individuals may wish to use phenylalanine supplements to increase their intake of this amino acid. Below are several issues related to this issue that may be considered. Please remember that this is not intended as professional medical advice. Prior to taking these supplements, look for qualified information related to the topic, and figure out whether it is recommended for you.


In the United States, the recommended daily allowance (RDA) of phenylalanine is 15 mg per pound of body weight. This, however, also includes tyrosine, as the body uses phenylalanine to make tyrosine.

Side effects

Phenylalanine supplements should not be taken by individuals with phenylketonuria. The same applies to pregnant women with hyperphenylalanine.

There may also be contraindications for people with certain medical conditions, such as schizophrenia (in which the supplements may make tardive dyskinesia, brought on by antipsychotic medicines, worse), and Parkinson's disease (in which some symptoms of the condition may be worsened).

Consider other side effects and contraindications, as well as any other precautions such as interactions, from a qualified source prior to taking these supplements. Tell your doctor or medical professional about any existing conditions and medications or other things you may be ingesting prior to taking this.


Taking phenylalanine can cause interactions with herbal medicines, medications, and other supplements. Some of these include antipsychotic medications (as previously mentioned), drugs with levodopa, and monoamine oxidase inhibitors (MAOIs). These are not intended to cover all potential interactions, so tell your doctor about any other supplements you are currently taking, as well as natural medicines and drugs, prior to beginning the use of phenylalanine supplements.

Breastfeeding women

No current information is available related to the safety of taking phenylalanine supplements while breastfeeding, so it is not recommended to do so. A normal dietary intake, on the other hand, is considered to be fine.