Tyrosine is a non-essential amino acid, meaning that it can either be obtained through your diet, or it can be naturally synthesized in your body as it is needed. N-acetyl L-tyrosine is a form of tyrosine which contains acetic acid, which could possibly increase tyrosine's bioavailability and absorption into your bloodstream. Tyrosine is needed in the formation of various neurotransmitters made in the adrenal glands and brain, as well as, is essential in the formation of thyroid hormone.