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.
Overview InformationTyrosine is an amino acid. Amino acids 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 most commonly used in protein supplements to treat an inherited disorder called phenylketonuria (PKU). People who have this disorder can't process phenylalanine properly. As a result they can't make tyrosine. To meet their bodies' needs, supplemental tyrosine is given.
Tyrosine is also commonly used to improve learning, memory, and alertness, especially during stressful situations.
How does it work?The body uses tyrosine to make chemical messengers that are involved in conditions involving the brain such as mental alertness.
Uses & Effectiveness
- Phenylketonuria (PKU). People with PKU are not able to process the amino acid phenylalanine. This amino acid is used by the body to make tyrosine. Because of this, people with PKU can have low levels of tyrosine in the body. To prevent tyrosine levels from becoming too low, people with PKU are advised to consume medical foods containing tyrosine but very little phenylalanine. Tyrosine levels in the blood are regularly measured by physicians.
Possibly Effective for
- Mental performance. Research shows that taking tyrosine improves mental performance under stressful conditions These include cold-induced stress or noise-induced stress.
- Memory. Research shows that taking tyrosine improves memory during stressful conditions. These include cold-induced stress or multi-tasking. Tyrosine does not seem to improve memory during less stressful situations.
- Improving alertness following the loss of sleep. Taking tyrosine helps people who have lost a night's sleep stay alert for about 3 hours longer than they otherwise would. Also, early research shows 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 improve symptoms in children or adults with ADHD.
- Depression. Taking tyrosine by mouth does not improve symptoms of depression.
- Exercise performance. Taking tyrosine before running or cycling does not improve strength, stamina, or performance.
Insufficient Evidence for
- Alcoholism. Early research shows that taking tyrosine along with other amino acids and a multivitamin reduces withdrawal symptoms and stress in alcoholics. It is not clear if this effect is due to tyrosine, other ingredients, or the combination.
- Cocaine dependence. Early research shows that taking tyrosine in the morning and L-tryptophan at night does not reduce cravings or withdrawal symptoms in people with cocaine dependence.
- Dementia. Early research shows that taking tyrosine, 5-hydroxytryptophan, and carbidopa by mouth does not improve symptoms in people with dementia.
- High blood pressure (hypertension). Early research shows that taking tyrosine by mouth does not reduce blood pressure in people with slightly high blood pressure.
- Excessive sleepiness (narcolepsy). Research shows that taking tyrosine by mouth reduces some symptoms of narcolepsy, such as feelings of tiredness, based on patient ratings. But it does not seem to improve most symptoms based on clinical assessment.
- Schizophrenia. Early research shows that taking tyrosine along with the drug molindone does not improve symptoms of schizophrenia better than molindone alone.
- Weight loss. Taking a combination of tyrosine, cayenne, green tea, caffeine, and calcium slightly reduces body fat by about 0.9 kg in overweight people. But the supplement does not improve blood pressure, heart rate, or the excretion of fat in the feces.
- Symptoms of heroin withdrawal. Early research shows that taking a combination of tyrosine, 5-hydroxytryptophan (HTP), phosphatidylcholine, and L-glutamine, improves mood and the ability to sleep in men addicted to heroin. It also seems to reduce withdrawal symptoms.
- Wrinkled skin. Applying a preparation containing 10% vitamin C, acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids seems to improve wrinkling, skin yellowing, roughness, and skin tone in people with sun-damaged skin.
- Alzheimer's disease.
- Chronic fatigue syndrome (CFS).
- Erectile dysfunction (ED).
- Heart disease.
- Parkinson's disease.
- Premenstrual syndrome (PMS).
- Other conditions.
Side Effects & SafetyTyrosine is LIKELY SAFE when taken by mouth in food amounts. It is POSSIBLY SAFE when taken by adults as a medicine, short-term, or when applied to the skin. Tyrosine seems to be safe when taken by mouth in doses up to 150 mg/kg per day for up to 3 months. Some people experience side effects such as nausea, headache, fatigue, and heartburn.
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.
Special Precautions & Warnings:Pregnancy and breast-feeding: There isn't enough information available to know if tyrosine is safe to use during pregnancy and breast-feeding. Stay on the safe side and only use in food amounts.
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.
Be cautious with this combination
Levodopa interacts with TYROSINE
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 hormone interacts with TYROSINE
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 mental performance: A single dose of 100-300 mg/kg of tyrosine has been taken before a stressful mental task.
- For memory: 150-300 mg/kg of tyrosine has been used before a memory task.
- For improving alertness following the loss of sleep: 150 mg/kg of tyrosine in a split dose has been used.
- For PKU: Foods and medical foods providing 4-6 grams of tyrosine daily are recommended. Women with PKU who are pregnant or breastfeeding are advised to consume foods providing 6-7.6 grams of tyrosine daily. A doctor will measure tyrosine levels in the blood to make sure they don't become too high or too low. For most people with PKU, additional separate supplementation with free tyrosine is not recommended. It can cause wide variations in the amount of tyrosine in the blood. This could cause unwanted side effects.
- 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.
- 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., 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Furst, P. Amino acid metabolism in uremia. J.Am.Coll.Nutr. 1989;8(4):310-323. 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.
- 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.
- 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.
- 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.
- 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.
- Meyers, S. Use of neurotransmitter precursors for treatment of depression. Altern Med Rev 2000;5(1):64-71. View abstract.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Tyrrell HA and Maher TJ. Tyrosine: Food supplement or therapeutic agent? Journal of Nutritional Medicine 1998;8(4):349-359.
- 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.
- Bjork JM, Grant SJ, Chen G, Hommer DW. Dietary tyrosine/phenylalanine depletion effects on behavioral and brain signatures of human motivational processing. Neuropsychopharmacology. 2014;39(3):595-604. View abstract.
- Chen D, Liu Y, He W, Wang H, Wang Z. Neurotransmitter-precursor-supplement intervention for detoxified heroin addicts. J Huazhong Univ Sci Technolog Med Sci 2012;32(3):422-7.
- Colzato LS, Jongkees BJ, Sellaro R, van den Wildenberg WP, Hommel B. Eating to stop: tyrosine supplementation enhances inhibitory control but not response execution. Neuropsychologia. 2014;62:398-402. View abstract,
- DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
- Dowlati Y, Ravindran AV, Maheux M, Steiner M, Stewart DE, Meyer JH. No effect of oral tyrosine on total tyrosine levels in breast milk: implications for dietary supplementation in early postpartum. Arch Womens Ment Health. 2014;17(6):541-8. View abstract.
- 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.
- 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.
- Singh RH, Rohr F, Frazier D, et al. Recommendations for the nutrition management of phenylalanine hydroxylase deficiency. Genet Med. 2014;16(2):121-31. View abstract.
- Steenbergen L, Sellaro R, Hommel B, Colzato LS. Tyrosine promotes cognitive flexibility: evidence from proactive vs. reactive control during task switching performance. Neuropsychologia. 2015;69:50-5. 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.
- Tumilty L, Davison G, Beckmann M, Thatcher R. Failure of oral tyrosine supplementation to improve exercise performance in the heat. Med Sci Sports Exerc. 2014;46(7):1417-25. View abstract.
- van de Rest O, Bloemendaal M, de Heus R, Aarts E. Dose-dependent effects of oral tyrosine administration on plasma tyrosine levels and cognition in aging. Nutrients 2017;9(12). pii: E1279. 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.
- Webster D, Wildgoose J. Tyrosine supplementation for phenylketonuria. Cochrane Database Syst Rev. 2013 5;(6):CD001507. 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.
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