L-Tyrosine is a conditionally indispensable amino acid required for the production of the neurotransmitters dopamine adrenaline and noradrenaline as well as for the skin pigment melanin.* Noradrenaline (norepinephrine) and adrenaline (epinephrine) are the main actors in the body's response to acute stress and along with dopamine help to support a positive mood and mental alertness.* In addition L-Tyrosine is especially critical for the normal function of the thyroid gland.*