Tyrosine is not an essential amino acid because the human body can manufacture tyrosine from Phenylalanine. Tyrosine forms three important neurotransmitters (serotonin, dopamine, and norepinephrine) that are responsible for memory, mood, appetite and the coordination of muscles. When these neurotransmitters are not in adequate amounts, a person may experience the feeling of nervousness, sadness, irritability and frustration. Studies show that L-tyrosine supplementation helps with anxiety and depression. Tyrosine also helps fight fatigue and irritability.
“In light of experimental data showing that the oral administration of tyrosine, precursor of the catecholamine series of neurotransmitters, can increase brain norepinephrine concentrations and activity, we have conducted preliminary trials of tyrosine in depressed outpatients.” ( J Psychiatr Res. 1982-1983;17(2):175-80. Tyrosine for depression.
Gelenberg AJ, Wojcik JD, Gibson CJ, Wurtman RJ.)
Dosage and Sources:
The typical therapeutic dosage for tyrosine used in studies ranges from 7 g to 30 g daily.
1. Neri DF, Wiegmann D, Stanny RR, et al. The effects of tyrosine on cognitive performance during extended wakefulness. Avit Space Environ Med. 1995;66:313-319.
2. Gelenberg AJ, Wojcik JD, Falk WE, et al. Tyrosine for depression: a double-blind trial. J Affect Disord. 1990; 19:125-132.
3. Reimherr FW, Wender PH, Wood RD, et al. An open trial of L-tyrosine in the treatment of attention deficit disorder, residual type. Am J Psychiatry. 1987;144:1071-1073.
4. Wood RD, Reimherr FW, Wender PH, et al. Amino acid precursors for the treatment of attention deficit disorder, residual type. Psychopharmacol Bull. 1985;21:146-149.
5. Gibson C, Gelenberg A. Tyrosine for the treatment of depression. Adv Biol Psychiatry. 1983;10:148-159.
Last update: January 17, 2009