Tyrosine is a white crystalline amino acid, CHNO, which is used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. Tyrosine is obtained from the hydrolysis of proteins such as casein and is a precursor of epinephrine, thyroxine, and melanin. It was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese.
Tyrosine supports and assists neurotransmitters in the brain. L-Tyrosine supplementation helps reduce stress, improves mental alertness and mood, acts as an appetite suppressant and has a positive affect on sex drive. Tyrosine, which can be synthesized in the body from phenylalanine, is found in many high protein food products such as soy products, chicken, turkey, fish, peanuts, almonds, avocados, bananas, milk, cheese, and yogurt.