Phenylalanine is an essential amino acid required for protein synthesis and the production of neurotransmitters such as dopamine, norepinephrine, and epinephrine. It exists in three forms: L-phenylalanine (natural form used in protein synthesis), D-phenylalanine, and a racemic mix DL-phenylalanine.
In supplements, L-phenylalanine is often used for its role in mood regulation, cognitive support, and nervous system function. For individuals who engage in physical activity, phenylalanine may contribute indirectly to mental focus and energy levels through its involvement in neurotransmitter production.
It is also a precursor to tyrosine, another amino acid important for thyroid hormone synthesis and metabolic function.
Synonyms:
L-Phenylalanine, DLPA (DL-Phenylalanine).
Benefits:
- Supports neurotransmitter production (dopamine, norepinephrine)
- Enhances mental focus and alertness
- Precursor to tyrosine and thyroid hormones
- May reduce fatigue during prolonged exercise
Sources:
Found in high-protein foods such as meat, dairy, eggs, soy, and legumes.
Observations:
Used in pre-workout and mood support supplements. Should be avoided by individuals with phenylketonuria (PKU), a genetic disorder. Excessive intake may cause headaches or anxiety in sensitive individuals.
Areas of Study Related:
Neurochemistry, Sports psychology, Nutritional biochemistry.