2-Acetylamino-3-(4-Hydroxyphenyl)-Propanoic Acid, Acetyl-L-Tyrosine, Acétyl-L-Tyrosine, L-Tyrosine, N-Acetyl L-Tyrosine, N-Acetyl-L-Tyrosine, N-Acétyl L-Tyrosine, N-Acetyl-Tyrosine, N-Acétyl-Tyrosine, Tirosina, Tyr, Tyrosinum, 2-amino-3-(4-hydroxyphenyl)propionic acid.
Tyrosine is one of the amino acids, which are the building blocks of protein. The body makes tyrosine from another amino acid called phenylalanine. Tyrosine can also be found in dairy products, meats, fish, eggs, nuts, beans, oats, and wheat.
Tyrosine is used in protein supplements to treat an inherited disorder called phenylketonuria (PKU). People who have this problem can't process phenylalanine properly, so as a result they can't make tyrosine. To meet their bodies' needs, supplemental tyrosine is given.
People take tyrosine for depression, attention deficit disorder (ADD), attention deficit-hyperactivity disorder (ADHD), the inability to stay awake (narcolepsy), and improving alertness following sleep deprivation. It is also used for stress, premenstrual syndrome (PMS), Parkinson's disease, Alzheimer's disease, chronic fatigue syndrome (CFS), alcohol and cocaine withdrawal, heart disease and stroke, ED (erectile dysfunction), loss of interest in sex, schizophrenia, and as a suntan agent and appetite suppressant.
Some people also apply tyrosine to the skin to reduce age-related wrinkles.
How does it work?
The body uses tyrosine to make chemical messengers that are involved in conditions involving the brain such as mental alertness.
- Phenylketonuria (PKU). People with PKU are not able to process the amino acid phenylalanine, which is used by the body to make tyrosine. Because of this, people with PKU can have low levels of tyrosine in the body. People with PKU are advised to consume 6 grams of tyrosine per 100 grams of protein to improve tyrosine levels in the body.
Possibly Effective for...
- Mental performance. Some early research suggests that taking tyrosine 2 hours before testing does not improve mood or speed of reaction to visual or noise stimuli in healthy people. However, several studies show that tyrosine improves mental performance under stressful conditions, such as military training, cold-induced stress, or noise-induces stress.
- Memory. Some early research suggests that taking tyrosine 2 hours before testing does not improve memory in healthy people. However, several studies show that tyrosine improves memory under stressful conditions, such as cold-stress or multitasking.
- Improving alertness following the loss of sleep. Taking 150 mg/kg of tyrosine seems to help people who have lost a night's sleep stay alert for about 3 hours longer than they otherwise would. Also, early research suggests that tyrosine improves memory and reasoning in people who are sleep-deprived.
Possibly Ineffective for...
- Attention deficit disorder (ADD). Taking tyrosine by mouth does not seem to improve symptoms of adult ADD.
- Attention deficit-hyperactivity disorder (ADHD). Taking tyrosine by mouth does not seem to improve symptoms of childhood ADHD.
- Depression. Taking tyrosine by mouth does not seem to improve symptoms of moderate depression.
- Exercise performance. Taking tyrosine before participating in treadmill walking with a load carriage does not seem to improve strength or endurance. Also, taking tyrosine, alone or with polydextrose 70, does not seem to improve heart rate or performance during a cycling test.
Insufficient Evidence to Rate Effectiveness for...
- Alcoholism. Early research suggests that taking a combination of D,L-phenylalanine, L-tyrosine, L-glutamine, and L-tryptophan along with a multivitamin might help reduce symptoms of withdrawal and decrease stress in alcoholics.
- Cocaine dependence. Early research suggests that taking L-tyrosine in the morning and L-tryptophan at night does not reduce drug cravings or withdrawal symptoms in people with cocaine dependence.
- Dementia. Early research suggests that taking a combination of tyrosine, 5-hydroxytryptophan (5-HTP), and carbidopa by mouth does not improve symptoms in people with severe dementia due to Alzheimer's disease or multi-infarct dementia.
- High blood pressure (hypertension). Early research suggests that taking tyrosine by mouth does not affect blood pressure in patients with slightly high blood pressure.
- Excessive sleepiness (narcolepsy). Research suggests that taking tyrosine by mouth might reduce some symptoms of narcolepsy, such as feelings of tiredness, based on patient ratings. However, it does not seem to improve most symptoms of narcolepsy based on clinical assessment.
- Schizophrenia. Early research suggests that taking L-tyrosine along with the drug molindone for 3 weeks does not improve symptoms of schizophrenia better than molindone alone.
- Weight loss. Taking a combination of tyrosine, cayenne, green tea, caffeine, and calcium for 8 weeks seems to slightly reduce body fat mass by 0.9 kg in overweight people. However, the combination supplement does not seem to improve blood pressure, heart rate, or the excretion of fat in the feces.
- Wrinkled skin. A topical preparation containing 10% vitamin C as L-ascorbic acid, acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids (Cellex-C High Potency Serum) applied for 3 months to facial skin aged by sunlight seems to improve fine and coarse wrinkling, yellowing, roughness, and skin tone.
- Premenstrual syndrome (PMS).
- Parkinson's disease.
- Chronic fatigue syndrome (CFS).
- Alzheimer's disease.
- Heart disease.
- Erectile dysfunction (ED).
- Other conditions.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
Tyrosine is LIKELY SAFE when taken by mouth in food amounts and POSSIBLY SAFE when taken by adults short-term in medicinal amounts or when applied to the skin. Tyrosine seems to be safe when used in doses up to 150 mg/kg per day for up to 3 months. Some people experience side effects such as nausea, headache, fatigue, heartburn, and joint pain.
There isn't enough information available to know if tyrosine is safe for children to use in medicinal amounts. Don't give it to children without the advice of your healthcare provider until more is known.
Overactive thyroid (hyperthyroidism) or Graves disease: The body uses tyrosine to make thyroxine, a thyroid hormone. Taking extra tyrosine might increase thyroxine levels too much, making hyperthyroidism and Graves disease worse. If you have one of these conditions, don't take tyrosine supplements.
LevodopaInteraction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Tyrosine might decrease how much levodopa the body absorbs. By decreasing how much levodopa the body absorbs, tyrosine might decrease the effectiveness of levodopa. Do not take tyrosine and levodopa at the same time.
Thyroid hormoneInteraction Rating: Moderate Be cautious with this combination.Talk with your health provider.
The body naturally produces thyroid hormones. Tyrosine might increase how much thyroid hormone the body produces. Taking tyrosine with thyroid hormone pills might cause there to be too much thyroid hormone. This could increase the effects and side effects of thyroid hormones.
The following doses have been studied in scientific research:
- For improving alertness after being without sleep for a long time: 150 mg/kg/day of tyrosine.
- For PKU: The current recommendation for people with PKU is the incorporation of 6 grams of tyrosine per 100 grams of protein. However, additional separate supplementation with free tyrosine is not recommended because it can produce wide variations in the amount of tyrosine in the blood and could cause unwanted side effects.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Alonso, Raf. Elevation of urinary catecholamines and their metabolites following tyrosine administration in humans. Biological Psychiatry 1982;17(7):781-790.
Alvestrand, A., Ahlberg, M., Furst, P., and Bergstrom, J. Clinical results of long-term treatment with a low protein diet and a new amino acid preparation in patients with chronic uremia. Clin.Nephrol. 1983;19(2):67-73. View abstract.
Alvestrand, A., Furst, P., and Bergstrom, J. Intracellular amino acids in uremia. Kidney Int.Suppl 1983;16:S9-16. View abstract.
Banderet, L. E. and Lieberman, H. R. Treatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans. Brain Res Bull 1989;22(4):759-762. View abstract.
Barrett, Sean P. and Leyton, Marco. Acute phenylalanine/tyrosine depletion: A new method to study the role of catecholamines in psychiatric disorders. Primary Psychiatry 2004;11(6):37-41.
Batshaw, M. L., Valle, D., and Bessman, S. P. Unsuccessful treatment of phenylketonuria with tyrosine. J.Pediatr. 1981;99(1):159-160. View abstract.
Belza, A. and Jessen, A. B. Bioactive food stimulants of sympathetic activity: effect on 24-h energy expenditure and fat oxidation. Eur.J.Clin.Nutr. 2005;59(6):733-741. View abstract.
Belza, A., Frandsen, E., and Kondrup, J. Body fat loss achieved by stimulation of thermogenesis by a combination of bioactive food ingredients: a placebo-controlled, double-blind 8-week intervention in obese subjects. Int.J.Obes.(Lond) 2007;31(1):121-130. View abstract.
Bergeron Anne, Jorquera Rossana Tanguay Robert M. Consequences of a deficit of the tyrosine catabolism pathway: Hereditary tyrosinemia type 1. M-S (Medecine Sciences). 2003;19(10):976-980.
Birkmayer, W. and Linauer, W. Disturbance of tyrosine and tryptophan metabolism in depression. Foreign Psychiatry 1972;1(3):209-222.
Bjerkensted, Lars, Farde, Lars, Terenius, Lars, Edman, Gunnar, Venizelos, Nikolaos, and Wiesel, Frits-Axel. Support for limited brain availability of tyrosine in patients with schizophrenia. International Journal of Neuropsychopharmacology 2006;9(2):247-255.
Bjerkenstedt, Lars. Decreased tyrosine transport in schizophrenic patients. In: Amino acids in psychiatric disease. American Psychiatric Association 1990;163-170.
Blum K. A commentary on neurotransmitter restoration as a common mode of treatment for alcohol, cocaine and opiate abuse. Integr Psychiatr 1986;6:199-204.
Bovier, Philippe, Widmer, Jean, Gaillard, Jean-Michel, and Tissot, René. Evolution of red blood cell membrane transport and plasma level of L-tyrosine and L-tryptophan in depressed treated patients according to clinical improvement. Neuropsychobiology 1988;19(3):125-134.
Chadwick, M. J., Gregory, D. L., and Wendling, G. A double-blind amino acids, L-tryptophan and L-tyrosine, and placebo study with cocaine-dependent subjects in an inpatient chemical dependency treatment center. Am J Drug Alcohol Abuse 1990;16(3-4):275-286. View abstract.
Chiaroni, Pierre, Pringuey, Dominique, Barre, A., and Widmer, J. Erythroplasma transfers of tyrosine and tryptophan in psychiatric patients: First results. Psychologie Medicale 1986;18(4):577-579.
Chinevere, T. D., Sawyer, R. D., Creer, A. R., Conlee, R. K., and Parcell, A. C. Effects of L-tyrosine and carbohydrate ingestion on endurance exercise performance. J Appl.Physiol 2002;93(5):1590-1597. View abstract.
Coupland, Nick, Zedkova, Lenka, Sanghera, Gurinder, Leyton, Marco, and Le Mellédo, Jean-Michel. Response to pentagastrin after acute phenylalanine and tyrosine depletion in healthy men: A pilot study. Journal of Psychiatry & Neuroscience 2001;26(3):247-251.
Deijen, J. B. and Orlebeke, J. F. Effect of tyrosine on cognitive function and blood pressure under stress. Brain Res Bull 1994;33(3):319-323. View abstract.
Deijen, J. B., Wientjes, C. J., Vullinghs, H. F., Cloin, P. A., and Langefeld, J. J. Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course. Brain Res Bull 1-15-1999;48(2):203-209. View abstract.
Deijen, Jan Berend. Tyrosine. Nutritional neuroscience. 2005;363-381.
Deutsch, Stephen I., Rosse, Richard B., Schwartz, Barbara L., and Banay-Schwartz, Miriam. L-tyrosine pharmacotherapy of schizophrenia: Preliminary data. Clinical Neuropharmacology 1994;17(1):53-62.
Dollins, A. B., Krock, L. P., Storm, W. F., Wurtman, R. J., and Lieberman, H. R. L-tyrosine ameliorates some effects of lower body negative pressure stress. Physiol Behav. 1995;57(2):223-230. View abstract.
Ellis, Kathryn A., Mehta, Mitul A., Murthy, P. J. Naga Venkatesha, McTavish, Sarah F. B., Nathan, Pradeep J., and Grasby, Paul M. Tyrosine depletion alters cortical and limbic blood flow but does not modulate spatial working memory performance or task-related blood flow in humans. Human Brain Mapping 2007;28(11):1136-1149.
Elwes, R. D., Crewes, H., Chesterman, L. P., Summers, B., Jenner, P., Binnie, C. D., and Parkes, J. D. Treatment of narcolepsy with L-tyrosine: double-blind placebo- controlled trial. Lancet 11-4-1989;2(8671):1067-1069. View abstract.
Flyckt, Lena, Venizelos, Nikolaos, Edman, Gunnar, Bjerkenstedt, Lars, Hagenfeldt, Lars, and Wiesel, Frits-Axel. Aberrant tyrosine transport across the cell membrane in patients with schizophrenia. Archives of General Psychiatry 2001;58(10):953-958.
Furst, P. Amino acid metabolism in uremia. J.Am.Coll.Nutr. 1989;8(4):310-323. View abstract.
Gelenberg, A. J. and Gibson, C. J. Tyrosine for the treatment of depression. Nutr Health 1984;3(3):163-173. View abstract.
Gelenberg, A. J., Wojcik, J. D., Growdon, J. H., Sved, A. F., and Wurtman, R. J. Tyrosine for the treatment of depression. Am J Psychiatry 1980;137(5):622-623. View abstract.
Gelenberg, Alan J., Wojcik, Joanne D., Gibson, Candace J., and Wurtman, Richard J. Tyrosine for depression. Journal of Psychiatric Research 1982;17(2):175-180.
Gibson, Candace J. and Gelenberg, Alan J. Tyrosine for the treatment of depression. Advances in Biological Psychiatry 1983;10:148-159.
Goldberg, I. K. L-tyrosine in depression. Lancet 8-16-1980;2(8190):364. View abstract.
Growdon, J. H., Melamed, E., Logue, M., Hefti, F., and Wurtman, R. J. Effects of oral L-tyrosine administration on CSF tyrosine and homovanillic acid levels in patients with Parkinson's disease. Life Sci. 3-8-1982;30(10):827-832. View abstract.
Hagenfeldt, L., Venizelos, N., Bjerkenstedt, L., and Wiesel, Frits-Axel. Decreased tyrosine transport in fibroblasts from schizophrenic patients. Life Sciences 1987;41(25):2749-2757.
Hao S, Avraham Y Bonne O Berry EM. Separation-induced body weight loss, impairment in alternation behavior, and autonomic tone: effects of tyrosine. Pharmacol Biochem Behav. 2001;68(2):273-281.
Harmer, C. J., McTavish, S. F. B., Clark, L., Goodwin, G. M., and Cowen, P. J. Tyrosine depletion attenuates dopamine function in healthy volunteers. Psychopharmacology 2001;154(1):105-111.
Kitahara, Michio. A precursor study of the indoleamine and catecholamine hypotheses of depression using the dietary tryptophan and tyrosine ratios. Journal of Orthomolecular Medicine 1990;5(4):210-214.
Lambert, M. I., Hefer, J. A., Millar, R. P., and Macfarlane, P. W. Failure of commercial oral amino acid supplements to increase serum growth hormone concentrations in male body-builders. Int.J.Sport Nutr. 1993;3(3):298-305. View abstract.
Lemoine, P., Robelin, N., Sebert, P., and Mouret, J. [L-tyrosine: a long term treatment of Parkinson's disease]. C.R.Acad Sci III 1989;309(2):43-47. View abstract.
Leyton, M., Young, Simon N., Pihl, R. O., Etezadi, S., Lauze, C., Blier, P., Baker, G. B., and Benkelfat, C. Effects on mood of acute phenylalanine/tyrosine depletion in healthy women. Neuropsychopharmacology 2000;22(1):52-63.
Leyton, Marco, Dagher, Alain, Boileau, Isabelle, Casey, Kevin, Baker, Glen B., Diksic, Mirko, Gunn, Roger, Young, Simon N., and Benkelfat, Chawki. Decreasing Amphetamine-Induced Dopamine Release by Acute Phenylalanine/Tyrosine Depletion: A PET/ [¹¹C]Raclopride Study in Healthy Men. Neuropsychopharmacology 2004;29(2):427-432.
Lou, H. Large doses of tryptophan and tyrosine as potential therapeutic alternative to dietary phenylalanine restriction in phenylketonuria. Lancet 7-20-1985;2(8447):150-151. View abstract.
Luciana, Monica, Sullivan, Jill, and Nelson, Charles A. Associations between phenylalanine-to-tyrosine ratios and performance on tests of neuropsychological function in adolescents treated early and continuously for phenylketonuria. Child Development 2001;72(6):1637-1652.
Lythe, Karen E., Anderson, I. M., Deakin, J. F. W., Elliott, R., and Strickland, P. L. Lack of behavioural effects after acute tyrosine depletion in healthy volunteers. Journal of Psychopharmacology 2005;19(1):5-11.
Ma, Yong, Ha, Zhende, Zhang, Xizhou, Wang, Wei, Cui, Jianhua, Zhang, Fang, and Zhu, Yongan. Effect of tyrosine and acetazolamide on the brain-body functions of healthy young men living in high altitudes. Chinese Mental Health Journal 2002;16(7):465-467.
Magill, R. A., Waters, W. F., Bray, G. A., Volaufova, J., Smith, S. R., Lieberman, H. R., McNevin, N., and Ryan, D. H. Effects of tyrosine, phentermine, caffeine D-amphetamine, and placebo on cognitive and motor performance deficits during sleep deprivation. Nutr.Neurosci. 2003;6(4):237-246. View abstract.
Mahoney, C. R., Castellani, J., Kramer, F. M., Young, A., and Lieberman, H. R. Tyrosine supplementation mitigates working memory decrements during cold exposure. Physiol Behav. 11-23-2007;92(4):575-582. View abstract.
McLean, Andrew, Rubinsztein, Judy S., Robbins, Trevor W., and Sahakian, Barbara J. The effects of tyrosine depletion in normal healthy volunteers: Implications for unipolar depression. Psychopharmacology 2004;171(3):286-297.
McTavish, S. F. B., McPherson, M. H., Harmer, C. J., Clark, L., Sharp, T., Goodwin, G. M., and Cowen, P. J. Antidopaminergic effects of dietary tyrosine depletion in healthy subjects and patients with manic illness. British Journal of Psychiatry 2001;179(4):356-360.
McTavish, S. F. B., McPherson, M. H., Sharp, T., and Cowen, P. J. Attenuation of some subjective effects of amphetamine following tyrosine depletion. Journal of Psychopharmacology 1999;13(2):144-147.
McTavish, Sarah F. B., Mannie, Zola N., Harmer, Catherine J., and Cowen, Philip J. Lack of Effect of Tyrosine Depletion on Mood in Recovered Depressed Women. Neuropsychopharmacology, 2005;30(4):786-791.
Mehta, Mitul A., Gumaste, Deepa, Montgomery, Andrew J., McTavish, Sarah F. B., and Grasby, Paul M. The effects of acute tyrosine and phenylalanine depletion on spatial working memory and planning in healthy volunteers are predicted by changes in striatal dopamine levels. Psychopharmacology 2005;180(4):654-663.
Meyers, S. Use of neurotransmitter precursors for treatment of depression. Altern Med Rev 2000;5(1):64-71. View abstract.
Montgomery, Andrew J., McTavish, Sarah F. B., Cowen, Philip J., and Grasby, Paul M. Reduction of Brain Dopamine Concentration With Dietary Tyrosine Plus Phenylalanine Depletion: An [¹¹C]Raclopride PET Study. American Journal of Psychiatry 2003;160(10):1887-1889.
Mouret, J., Lemoine, P., Sanchez, P., Robelin, N., and Canini, F. \ET/ Treatment of narcolepsy with L-tyrosine. Lancet (England) 1988;2:1458-1459.
Mouret, J., Lemoine, P., Sanchez, P., Robelin, N., Taillard, J., and Canini, F. Treatment of narcolepsy with L-tyrosine. Lancet 12-24-1988;2(8626-8627):1458-1459. View abstract.
Munafo, Marcus R., Mannie, Zola N., Cowen, Philip J., Harmer, Catherine J., and McTavish, Sarah B. Journal of Effects of acute tyrosine depletion on subjective craving and selective processing of smoking-related cues in abstinent cigarette smokers. Psychopharmacology 2007;21(8):805-814.
O'Brien, C., Mahoney, C., Tharion, W. J., Sils, I. V., and Castellani, J. W. Dietary tyrosine benefits cognitive and psychomotor performance during body cooling. Physiol Behav. 2-28-2007;90(2-3):301-307. View abstract.
Owasoyo, Joseph O., Neri, David F., and Lamberth, John G. Tyrosine and its potential use as a countermeasure to performance decrement in military sustained operations. Aviation, Space, and Environmental Medicine 1992;63(5):364-369.
Palinkas, L. A., Reedy, K. R., Smith, M., Anghel, M., Steel, G. D., Reeves, D., Shurtleff, D., Case, H. S., Van, Do N., and Reed, H. L. Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence. Int.J.Circumpolar.Health 2007;66(5):401-417. View abstract.
Porter, Richard J., Mulder, Roger T., Joyce, Peter R., and Luty, Suzanne E. Tryptophan and tyrosine availability and response to antidepressant treatment in major depression. Journal of Affective Disorders 2005;86(2-3):129-134.
Pringuey, D., Bovier, P., Chiaroni, P., and Widmer, J. Membrane transport of L-tyrosine and L-tryptophan in red blood cells: Preliminary results in a group of 66 depressed patients. Acta Psychiatrica Belgica 1986;86(2):131-140.
Rasmussen, D. D., Ishizuka, B., Quigley, M. E., and Yen, S. S. Effects of tyrosine and tryptophan ingestion on plasma catecholamine and 3,4-dihydroxyphenylacetic acid concentrations. J.Clin.Endocrinol.Metab 1983;57(4):760-763. View abstract.
Reinstein, D. K., Lehnert, H., and Wurtman, R. J. Dietary tyrosine suppresses the rise in plasma corticosterone following acute stress in rats. Life Sci. 12-9-1985;37(23):2157-2163. View abstract.
Roiser, Jonathan P., McLean, Andrew, Ogilvie, Alan D., Blackwell, Andrew D., Bamber, Diane J., Goodyer, Ian, Jones, Peter B., and Sahakian, Barbara J. The Subjective and Cognitive Effects of Acute Phenylalanine and Tyrosine Depletion in Patients Recovered from Depression. Neuropsychopharmacology 2005;30(4):775-785.
Ryan, M. M., Sy, C., Rudge, S., Ellaway, C., Ketteridge, D., Roddick, L. G., Iannaccone, S. T., Kornberg, A. J., and North, K. N. Dietary L-tyrosine supplementation in nemaline myopathy. J.Child Neurol. 2008;23(6):609-613. View abstract.
Salter, Charles A. Dietary tyrosine as an aid to stress resistance among troops. Military Medicine 1989;154(3):144-146.
Shaw, D. M., Tidmarsh, S. F., Johnson, A. L., Michalakeas, A. C., Riley, G. J., Blazek, R., MacSweeney, D. A., Francis, A. F., and Hewland, R. Multicompartmental analysis of amino acids. III. Tyrosine in affective disorder. Psychol Med 1979;9(1):117-123. View abstract.
Sheehan, B. D., Tharyan, P., McTavish, S. F. B., Campling, G. M., and Cowen, P. J. Use of a dietary manipulation to deplete plasma tyrosine and phenylalanine in healthy subjects. Journal of Psychopharmacology 1996;10(3):231-234.
Shurtleff, D., Thomas, J. R., Schrot, J., Kowalski, K., and Harford, R. Tyrosine reverses a cold-induced working memory deficit in humans. Pharmacol Biochem Behav 1994;47(4):935-941. View abstract.
Smith, M. L., Hanley, W. B., Clarke, J. T., Klim, P., Schoonheyt, W., Austin, V., and Lehotay, D. C. Randomised controlled trial of tyrosine supplementation on neuropsychological performance in phenylketonuria. Arch Dis Child 1998;78(2):116-121. View abstract.
Sole, M. J., Benedict, C. R., Myers, M. G., Leenen, F. H., and Anderson, G. H. Chronic dietary tyrosine supplements do not affect mild essential hypertension. Hypertension 1985;7(4):593-596. View abstract.
Struder, H. K., Hollmann, W., Platen, P., Donike, M., Gotzmann, A., and Weber, K. Influence of paroxetine, branched-chain amino acids and tyrosine on neuroendocrine system responses and fatigue in humans. Horm Metab Res 1998;30(4):188-194. View abstract.
Sutton, E. E., Coill, M. R., and Deuster, P. A. Ingestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance. Int.J.Sport Nutr.Exerc.Metab 2005;15(2):173-185. View abstract.
Tam, See-Ying Author and Roth, Robert H. Reprint author. Mesoprefrontal dopaminergic neurons: Can tyrosine availability influence their functions? Biochemical Pharmacology. 1997;53(4):441-453.
Thomas, J. R., Lockwood, P. A., Singh, A., and Deuster, P. A. Tyrosine improves working memory in a multitasking environment. Pharmacol Biochem Behav 1999;64(3):495-500. View abstract.
Tissot, R. Uptake of tryptophan and tyrosine in some cases of manic depressive psychosis and schizophrenia. Neuropsychobiology 1978;4(2):65-73.
Tyrrell HA and Maher TJ. Tyrosine: Food supplement or therapeutic agent? Journal of Nutritional Medicine 1998;8(4):349-359.
Van Praag, H. M. In search of the mode of action of antidepressants: 5-HTP/tyrosine mixtures in depressions. Neuropharmacology 1983;22(3B):433-440.
van Spronsen, F. J. Reprint author, Smit, P. G. A. Author, and Koch, R. Author. Phenylketonuria: Tyrosine beyond the phenylalanine-restricted diet. Journal of Inherited Metabolic Disease. 2001;24(1):1-4.
van Spronsen, F. J., van Dijk, T., Smit, G. P., van Rijn, M., Reijngoud, D. J., Berger, R., and Heymans, H. S. Large daily fluctuations in plasma tyrosine in treated patients with phenylketonuria. Am J Clin Nutr 1996;64(6):916-921. View abstract.
Vrshek-Schallhorn, Suzanne, Wahlstrom, Dustin, Benolkin, Kelly, White, Tonya, and Luciana, Monica. Affective Bias and Response Modulation Following Tyrosine Depletion in Healthy Adults. Neuropsychopharmacology 2006;31(11):2523-2536.
Wei, Jun, Xu, Haimin, Ramchand, C. N., and Hemmings, Gwynneth P. Low concentrations of serum tyrosine in neuroleptic-free schizophrenics with and early onset. Schizophrenia Research 1995;14(3):257-260.
Widmer, J., Gaillard, J.-M., Dick, P., and Tissot, R. Exchange mechanism of tyrosine between plasma and red blood cells in normal subjects and psychiatric patients. Neuropsychobiology 1982;8(4):198-204.
Wiesel, F. A., Venizelos, N., Bjerkenstedt, L., and Hagenfeldt, L. Tyrosine transport in schizophrenia. Schizophrenia Research 1994;13(3):255-258.
Woods SK, Meyer JS. Exogenous tyrosine potentiates the methylphenidate-induced increase in extracellular dopamine in the nucleus accumbens: a microdialysis study. Brain Res. 1991;560(1-2):97-105.
Young, Simon N. Psychopharmacology for the clinician: Psychopharmacologie pratique: L-Tyrosine to alleviate the effects of stress? Journal of Psychiatry & Neuroscience 2007;32(3):224.
DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
Eisenberg J, Asnis GM, van Praag HM, Vela RM. Effect of tyrosine on attention deficit disorder with hyperactivity. J Clin Psychiatr 1988;49:193-5. View abstract.
Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
Food and Nutrition Board, Institute of Medicine. The Role of Protein and Amino Acids in Sustaining and Enhancing Performance. Washington, DC: National Academy Press, 1999. Available at: http://www.nap.edu/books/0309063469/html/.
Gelenberg AJ, Wojcik JD, Falk WE, et al. Tyrosine for depression: a double-blind trial. J Affect Disord 1990;19:125-32. View abstract.
Hitsman, Brian, MacKillop, James, Lingford-Hughes, Anne, Williams, Tim M., Ahmad, Faheem, Adams, Sally, Nutt, David J., and Munaf®, Marcus R. Effects of acute tyrosine/phenylalanine depletion on the selective processing of smoking-related cues and the relative value of cigarettes in smokers. Psychopharmacology 2008;196(4):611-621.
Lieberman HR, Corkin S, Spring BJ. The effects of dietary neurotransmitter precursors on human behavior. Am J Clin Nutr 1985;42:366-70. View abstract.
Meyer JS, Welch KM, Deshmukh VD, et al. Neurotransmitter precursor amino acids in the treatment of multi-infarct dementia and Alzheimer's disease. J Amer Geriat Soc 1977;25:289-98. View abstract.
Neri DF, Wiegmann D, Stanny RR, et al. The effects of tyrosine on cognitive performance during extended wakefulness. Aviat Space Environ Med 1995;66:313-9. View abstract.
NIH Consensus Statement. Phenylketonuria: Screening and Management. October 16-18, 2000. Pediatrics 2001;108:972-82. View abstract.
Poustie VJ, Rutherford P. Tyrosine supplementation for phenylketonuria. Cochrane Database Syst Rev 2000;2:CD001507. View abstract.
Reimherr FW, Wender PH, Wood DR, Ward M. An open trial of L-tyrosine in the treatment of attention deficit disorder, residual type. Am J Psychiatr 1987;144:1071-3. View abstract.
Roberts SA, Thorpe JM, Ball RO, Pencharz PB. Tyrosine requirement of healthy men receiving a fixed phenylalanine intake determined by using indicator amino acid oxidation. Am J Clin Nutr 2001 Feb;73:276-82. View abstract.
Traikovich SS. Use of topical ascorbic acid and its effects on photodamaged skin topography. Arch Otolaryngol Head Neck Surg 1999;125:1091-8. View abstract.
van Spronsen FJ, van Rijn M, Bekhof J. Phenylketonuria: tyrosine supplementation in phenylalanine-restricted diets. Am J Clin Nutr 2001;73:153-7. View abstract.
Wood DR, Reimherr FW, Wender PH. Amino acid precursors for the treatment of attention deficit disorder, residual type. Psychopharmacol Bull 1985;21:146-9.