L-phenylalanine is an essential amino acid and direct precursor to tyrosine → dopamine → norepinephrine → epinephrine. DL-phenylalanine (DLPA) combines L-form (catecholamine precursor) with D-form (endorphin protector — inhibits enkephalinase, prolonging endogenous pain-killing opioid activity). DLPA at 750-1,500mg/day used for chronic pain and depression. CONTRAINDICATED in PKU (phenylketonuria). Interacts with MAOIs (hypertensive crisis risk). --- *Reviewed by the Dose AI Research Team and Clinical Advisory Board* *Last updated: 2026-04-06*
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated:
Not medical advice. Based on published clinical research and systematic reviews.