Tyrosine is a non-essential amino acid synthesized in the body from the essential amino acid phenylalanine. Tyrosine is the direct precursor to several important neurotransmitters, such as dopamine, norepinephrine, dpinephrine, and L-dopa. Some of the functions regulated by these tyrosine-dependant neurotransmitters include mood, stress response, mental function, satiety and sex drive.
Tyrosine is also an important component of hormones that are produced by the thyroid. These hormones are in turn vital for managing metabolism. Tyrosine is required to form melanin, the dark pigment that provides protection from the harmful effects of ultraviolet light.
Dairy products, meats, fish, wheat, oats and many other foods contain tyrosine
1 to 10 grams daily.
Most Common Dosage
500mg, 3 times daily.
Tablets, capsules, powder, and liquid.
Interactions and Depletions
Because tyrosine affects the production of the neurotransmitter dopamine, it has been used to treat cocaine abuse. Cocaine depletes the body of natural dopamine and creates an addiction to dopamine delivered by use of the drug. Tyrosine helps the body synthesize more dopamine rather than relying on cocaine. (1)
Phenylketonuria (PKU) is a genetic inborn error of not being able to convert phenylalanine to tyrosine. If the condition is caught early and a phenylalanine elimination-diet is applied, normal development may be possible. (2) Another study found PKU patients experienced high concentrations of phenylketonuria when on a poorly controlled diet. (3) Tyrosine supplementation seemed to help support normal protein and catecholamine synthesis. (4) , (5)
Results of a study involving end-stage renal disease (ESRD) patients found that because of a reduced conversion of phenylalanine to tyrosine the patients suffered from tyrosine deficiency and that tyrosine supplementation may be required. (6)
Since tyrosine is the precursor for dopamine and another neurotransmitter, norepinephrine, it has been used with some success in the treatment of depression. (7) Some physicians also suggest that tyrosine can help alleviate the depression that often accompanies Parkinson’s disease and Alzheimer’s disease. (8) , (9) , (10)
Tyrosine is also the precursor for epinephrine, another important neurotransmitter. Epinephrine is responsible for helping us manage the body’s responses to stress. Studies suggest that tyrosine’s enhancement of epinephrine production may reduce effects of stress like short term memory loss and depression. (11) , (12)
Toxicities & Precautions
[span class=alert]Be sure to tell your pharmacist, doctor, or other health care providers about any dietary supplements you are taking. There may be a potential for interactions or side effects.[/span]
This dietary supplement is considered safe when used in accordance with proper dosing guidelines.
Occasional side effects reported with large doses of this dietary supplement include diarrhea, nausea, vomiting or nervousness. It may be necessary to reduce the dose of this dietary supplement. Tell your doctor if these side effects become severe or do not go away.
Pregnancy / Breast Feeding
To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Yet little is known about the use of this dietary supplement while pregnant or breast-feeding. Therefore, it is recommended that you inform your healthcare practitioner of any dietary supplements you are using while pregnant or breast-feeding.
To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.
- Blum K, et al. Reduction of both drug hunger and withdrawal against advice rate of cocaine abusers in a 30 day inpatient treatment program by the neuronutrient Tropamine. Curr Ther Research. 1988;43:1204.
- View Abstract: Mira NV, Marquez UM. Importance of the diagnoses and treatment of phenylketonuria. Rev Saude Publica. Feb2000;34(1):86-96.
- View Abstract: Schulpis KH, Papassotiriou I, Vounatsou M, Karikas GA, Tsakiris S, Chrousos GP. Morning preprandial plasma ghrelin and catecholamine concentrations in patients with phenylketonuria and normal controls: evidence for catecholamine-mediated ghrelin regulation. J Clin Endocrinol Metab. Aug2004;89(8):3983-7.
- View Abstract: van Spronsen FJ, van Rijn M, Bekhof J, et al. Phenylketonuria: tyrosine supplementation in phenylalanine-restricted diets. J Inherit Metab Dis. Feb2001;73(2):153-7.
- View Abstract: Rohr FJ. Tyrosine supplementation in the treatment of maternal phenylketonuria. J Clin Nutr. Mar1998;67(3):473-6.
- View Abstract: Boirie Y, Albright R, Bigelow M, Nair KS. Impairment of phenylalanine conversion to tyrosine in end-stage renal disease causing tyrosine deficiency. Kidney Int. Aug2004;66(2):591-6.
- View Abstract: Gelenberg AJ, Gibson CJ. Tyrosine for the treatment of depression. Nutr Health. 1984;3(3):163-73.
- Braverman ER, et al. The Healing Nutrients Within. New Canaan, CT: Keats Publishing; 1997:59-68.
- View Abstract: Meyer JS, et al. Neurotransmitter precursor amino acids in the treatment of multi-infarct dementia and Alzheimer’s disease. J Am Geriatr Soc. Jul1977;25(7):289-98.
- View Abstract: Growdon JH, et al. Effects of oral L-tyrosine administration on CSF tyrosine and homovanillic acid levels in patients with Parkinson’s disease. Life Sci. Mar1982;30(10):827-32.
- View Abstract: Lehnert H, et al. Neurochemical and behavioral consequences of acute, uncontrollable stress: effects of dietary tyrosine. Brain Res. Jun1984;303(2):215-23.
- View Abstract: Shurtleff D, et al. Tyrosine reverses a cold-induced working memory deficit in humans. Pharmacol Biochem Behav. Apr1994;47(4):935-41.