Phenylalanine
Essential precursor to tyrosine and brain chemicals.
What is Phenylalanine?
Phenylalanine is an essential amino acid the body converts into tyrosine, which in turn becomes the neurotransmitters dopamine, norepinephrine and epinephrine, plus thyroid hormones and the pigment melanin. People with the genetic condition PKU must limit it.
Health benefits of Phenylalanine
- Converted to tyrosine, then to dopamine and norepinephrine
- Supports alertness, mood and the stress response
- A precursor for thyroid hormones and melanin
- A building block of countless body proteins
Top food sources of Phenylalanine
See full rankingMeat, fish, eggs, dairy, soy and other legumes, nuts and seeds. Values shown per 100 g.
Egg, white, dried, powder, glucose reduced
5,181 mg
Egg, white, dried, flakes, glucose reduced
4,837 mg
Egg, white, dried
4,736 mg
Soy protein isolate, PROTEIN TECHNOLOGIES INTERNATIONAL, SUPRO
4,600 mg
Soy protein isolate
4,593 mg
Soy protein isolate, potassium type
4,593 mg
Soy protein isolate, potassium type, crude protein basis
4,593 mg
Soy protein isolate, PROTEIN TECHNOLOGIES INTERNATIONAL, ProPlus
4,500 mg
Soy protein concentrate, produced by alcohol extraction
3,278 mg
Soy protein concentrate, produced by acid wash
3,278 mg
Soy protein concentrate, crude protein basis (N x 6.25), produced by acid wash
3,278 mg
Seal, bearded (Oogruk), meat, dried (Alaska Native)
3,275 mg
How much Phenylalanine do you need?
There is no FDA Daily Value for individual amino acids. The WHO estimate for phenylalanine plus tyrosine is about 25 mg per kg of body weight per day.
Phenylalanine deficiency
Deficiency is rare. The opposite matters for people with phenylketonuria (PKU), who lack the enzyme to process it and must follow a restricted diet.
Nutrition data per 100 g from the USDA & FooDB databases. Daily Values follow the FDA 2016+ labeling standard for a 2,000-calorie diet. This guide is for general information and is not medical advice.
Frequently asked questions
What does Phenylalanine do?
Phenylalanine is an essential amino acid the body converts into tyrosine, which in turn becomes the neurotransmitters dopamine, norepinephrine and epinephrine, plus thyroid hormones and the pigment melanin. People with the genetic condition PKU must limit it.
How much Phenylalanine do I need per day?
There is no FDA Daily Value for individual amino acids. The WHO estimate for phenylalanine plus tyrosine is about 25 mg per kg of body weight per day.
Which foods are highest in Phenylalanine?
Per 100 g, some of the richest sources are Egg, white, dried, powder, glucose reduced, Egg, white, dried, flakes, glucose reduced, Egg, white, dried, Soy protein isolate, PROTEIN TECHNOLOGIES INTERNATIONAL, SUPRO, Soy protein isolate.
What happens if I don't get enough Phenylalanine?
Deficiency is rare. The opposite matters for people with phenylketonuria (PKU), who lack the enzyme to process it and must follow a restricted diet.