Tyrosine is another non-essential amino acid. The body manufactures tyrosine and uses it to make neurotransmitters like dopamine, epinephrine (adrenaline), norepinaphrine, etc. It is also necessary for the synthesis of thyroid hormones, and it is a precursor of melanin. Deficiencies are rare, but they can occur in some forms of kidney disease and phenylketonuria.


  • Helps fight fatigue in people deprived of sleep
  • Increases mental alertness
  • Possesses antidepressant properties against stress
  • Temporary benefits for attention deficit disorder

Tyrosine should not be taken by persons on monoamine oxidase inhibitors. People with melanoma or high blood pressure should also consult with a qualified and experienced health professional before taking tyrosine.

Tyrosine seems to be generally safe, though at high doses some people have reported side effects such as diarrhea, nausea, nervousness or vomiting.