PHENYLALANINE

Phenylalanine is well established as an essential amino acid and the metabolic precursor to tyrosine and subsequently catecholamines. Research on phenylalanine supplementation for mood and pain is limited but suggests modest benefit in some populations, particularly for mild depression when combined with other precursors. Elevated phenylalanine levels are neurotoxic, as demonstrated in phenylketonuria (PKU) where PAH deficiency causes intellectual disability and behavioral problems. Recent work links dysregulated phenylalanine catabolism to cardiac aging via cellular senescence pathways. Evidence for cognitive enhancement in healthy individuals is weak and largely anecdotal.