Evidence supporting the use of: L-phenylalanine
For the body system: Specific Neurotransmitters

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Table of Contents

Synopsis

Source of validity: Scientific
Rating (out of 5): 2

L-phenylalanine is an essential amino acid that serves as a precursor to the amino acid tyrosine, which in turn is a precursor to key neurotransmitters such as dopamine, norepinephrine, and epinephrine. Because of this biochemical role, L-phenylalanine has been investigated for its potential to support neurotransmitter synthesis and thus influence mood and cognitive function. Some small studies and clinical trials have explored its use in conditions like depression, with mixed results. For example, limited evidence from the 1970s and 1980s suggested possible antidepressant activity, but these studies were generally small, lacked rigorous controls, or have not been widely replicated. More recent scientific reviews and clinical guidelines do not support the use of L-phenylalanine as a primary or adjunctive treatment for depression or other neuropsychiatric disorders due to insufficient robust evidence. The theoretical justification is sound based on its role in neurotransmitter biosynthesis, but clinical validation remains limited and inconsistent. Therefore, while the use of L-phenylalanine to support neurotransmitter function has some scientific basis, the quality and quantity of evidence are modest at best, warranting a low-to-moderate evidence rating.

More about l-phenylalanine
More about Specific Neurotransmitters

Other body systems supported by l-phenylalanine

Brain
Dopamine
Nerves
Specific Neurotransmitters

Products containing l-phenylalanine

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Metagenics Ultra Glucose Control® Chocolate
Metagenics Ultra Glucose Control Chocolate
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Metagenics Ultra Glucose Control Vanilla
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Metagenics UltraGI Replenish Chocolate
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Metagenics UltraInflamX Plus 360°® Chocolate/Orange
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Metagenics UltraInflamX Plus 360° Orange
Metagenics UltraInflamX Plus 360° Original Spice
Metagenics UltraInflamX Plus 360° Pineapple/Banana
Metagenics UltraInflamX Plus 360° Pineapple/Banana
Metagenics UltraMeal Advanced Protein® Dutch Chocolate
Metagenics UltraMeal Advanced Protein French Vanilla
Metagenics UltraMeal Advanced Protein Plain
Metagenics UltraMeal Cardio 360°® Pea/Rice Chocolate
Metagenics UltraMeal Cardio 360° Pea/Rice Vanilla