L-Phenylalanine
Phenylalanine is an essential amino acid that comes from food and is the starting material for tyrosine.
PKU requires a different approach
Phenylketonuria, or PKU, impairs phenylalanine processing. Excess can accumulate and damage the brain. People with PKU need a carefully controlled diet and medical follow-up; uncontrolled maternal PKU can also harm fetal development. 1
What does a safety assessment establish?
In 2016, Norway’s VKM judged specified supplemental L-phenylalanine doses from 100 to 1,000 mg daily unlikely to harm healthy adults. Its conclusion excludes PKU. Long-term data were inadequate to establish an upper intake limit, so these assessed doses are not a personal dosing recommendation. 2
For information, not individual medical advice. Ingredient studies do not establish the effectiveness of these products.
Sources
- Phenylketonuria MedlinePlus Genetics