Phenylalanine and hormones
Phenylalanine is a precursor to tyrosine which leads to the manufacture of dopamine, noradrenalin, thyroxine and melanin. As we have discussed previously, increased levels of dopamine are required by people suffering with Parkinson's Disease. (see leucine)

When there are reduced levels of noradrenalin in the brain then depression accompanied by fatigue may be the result. Thyroxin is important for normal growth and mental development in children, normal nervous system activity, blood ,flow and pressure and proper gastrointestinal activity.

Melanin is a pigment produced by the body to help screen out harmful ultraviolet rays and is the pigment that gives us our "tan".


Phenylalanine is also known as an analgesic which is slower acting than many analgesics, but pain relief is longer in duration: it has the added benefit of helping other analgesics such as flavanoids and aspirin work better. (see Pain)
Gastric acid secretions are also potentiated by phenylalanine so digestion is greatly enhanced.