Tyrosine is in all tissues of the human body and in most of its fluids. It helps the body build proteins in your body, and produce enzymes, thyroid hormones, and the skin pigment melanin. It also helps the body produce neurotransmitters that help nerve cells communicate. Tyrosine is particularly important in the production of epinephrine, norepinephrine, and dopamine. It helps form important brain chemicals that affect mood and sleep.

Most people do not need to take L-tyrosine because their bodies have a mechanism for regulating tyrosine supply. If you do not consume enough tyrosine from food, your body can make more. If you consume too much, your body will break it down and get rid of it.