Table of ContentsView AllTable of ContentsUses of L-TyrosineSide EffectsPrecautionsDosageInteractionsStorageFrequently Asked QuestionsSources & What to Look For
Table of ContentsView All
View All
Table of Contents
Uses of L-Tyrosine
Side Effects
Precautions
Dosage
Interactions
Storage
Frequently Asked Questions
Sources & What to Look For
While tyrosine supplements are generally safe, they’re not right for everyone. Those with an overactive thyroid (hyperthyroidism) should avoid it, as tyrosine may increase thyroid hormone production. People who get migraines may experience an increase in symptoms with tyrosine supplementation.It’s always best to consult a healthcare provider before adding any supplement to your routine.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
Tyrosine is made in the body from another amino acid calledphenylalanine. It is used in the body to make the catecholaminesdopamineandnorepinephrine. Under stressful conditions, thesecatecholaminescan be depleted.
Tyrosine is marketed for stress relief, brain health, and improved cognitive function. It is also thought to stimulate thyroid hormone production in people withhypothyroidism(low thyroid function), including those withHashimoto thyroiditis(the autoimmune form of hypothyroidism).
To date, there is very little evidence to support any of these claims, and most of the evidence involves small studies with variable results.
Getty Images / Olena Ruban
Improved Cognitive Function During Physical Stress
Tyrosine is often marketed to alleviate the effects of stress. The definition of stress is left open to interpretation, but the research supporting tyrosine evaluated its effects during periods of extreme physical stress.
During periods of physical stress, the body releases more catecholamines, resulting in a depletion of their levels.
Studies have evaluated anywhere from 2 grams (g) to 20 g of tyrosine on cognitive performance during periods of prolonged sleep deprivation,exposure to extremely cold temperatures,or during demanding military combat training.
In another study, tyrosine supplementation improved cognitive functioning, such as response inhibition, task switching, and working memory in young adults. However, this was mostly seen in short-term stressful situations or cognitively demanding scenarios.
These studies show improved cognitive function with tyrosine supplementation during extreme physical stress. Therefore, these results don’t necessarily apply to the general population, who may experience mild stress from psychosocial factors or daily activities.
Additionally, taking tyrosine will not help you feel less stressed, which some may mistakenly interpret from the marketing claims.
Phenylketonuria (PKU)
Phenylketonuria (PKU)is an inherited disorder in which the person cannot process phenylalanine appropriately.
Since phenylalanine converts to tyrosine, this could lead to low levels of tyrosine in the body. People with PKU may be advised to consume a diet containing tyrosine and very little phenylalanine to prevent low tyrosine levels.
Research that evaluated tyrosine supplementation in people with PKU found that tyrosine levels in the blood were higher with supplementation. However, there was no difference between the supplement or placebo group in any of the other outcomes measured.
What to Eat When You Have PKU
What Are the Side Effects of L-Tyrosine?
Some have reported nausea, fatigue, and headaches with tyrosine supplementation.
There is insufficient data on the safety of supplementing tyrosine in pregnant or breastfeeding people. Therefore, sticking to amounts of tyrosine found naturally in foods is safest.
People withhyperthyroidism(overactive thyroid gland) should avoid tyrosine supplements as they can increase thyroid hormone production and worsen symptoms of hyperthyroidism (includingGraves' disease, the autoimmune form of hyperthyroidism).
Tyrosine can also trigger migraine headaches. If you have frequent migraines, avoid tyrosine supplementation.
Dosage: How Much L-Tyrosine Should I Take?
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
Tyrosine is available in the foods that we eat. Therefore, most people get enough tyrosine from their diet alone.
For adults, the estimated amino acid requirement for phenylalanine and tyrosine combined is 14 mg/kg body weight daily.
Dosage may vary depending on what you’re taking it for. Talk to a healthcare provider or a registered dietitian nutritionist on the most appropriate dosing regimen for you
There is not a lot of data on the effects of high doses of tyrosine or toxicity. The possible ill effects of such high doses over the long term are not known.
Some medications may interact with supplemental tyrosine:
It is essential to carefully read the ingredients list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included. Review the supplement label with your healthcare provider to discuss any potential interactions with foods, other supplements, and medications.
How to Store L-Tyrosine
Store tyrosine as you would for other supplements, following the manufacturer’s guidelines for the best shelf life. Always store supplements and medications out of the reach of children and pets to prevent accidental consumption.
Frequently Asked QuestionsHigh-protein foods such as meats, chicken, turkey, fish, and eggs are good sources of tyrosine. You can also get it in some cheeses, like cheddar and cottage cheese, and yogurt.There is not enough evidence to suggest that tyrosine alone can improve performance. Preliminary research has found that caffeine, theanine, and tyrosine may improve performance,but caffeine is already known to be an ergogenic aid. Tyrosine also did not improve performance in a hot environment.It also did not have a measurable effect on endurance, muscle strength, or power in healthy men.More research is needed before tyrosine supplementation can be routinely recommended.
High-protein foods such as meats, chicken, turkey, fish, and eggs are good sources of tyrosine. You can also get it in some cheeses, like cheddar and cottage cheese, and yogurt.
There is not enough evidence to suggest that tyrosine alone can improve performance. Preliminary research has found that caffeine, theanine, and tyrosine may improve performance,but caffeine is already known to be an ergogenic aid. Tyrosine also did not improve performance in a hot environment.It also did not have a measurable effect on endurance, muscle strength, or power in healthy men.More research is needed before tyrosine supplementation can be routinely recommended.
Sources of L-Tyrosine & What To Look For
Tyrosine is easy to get through diet alone. High tyrosine foods include:
Tyrosine supplementation can be found in its free form. It can also be found as N-acetyl L-Tyrosine (NALT). The conversion rate of NALT to tyrosine is lower so some may take higher doses of NALT.
Tyrosine is available as a combination product, with high amounts of several B vitamins. It can also be found combined with iodine. Products are often marketed and labeled for “brain health,” “neurotransmitter support during stress,” or “thyroid support.” As mentioned previously, there is little evidence to support these claims.
When looking for supplements,be sure to find ones that have been independently testedso that you can trust they contain what the label claims and are free of harmful contaminants.
Summary
Tyrosine is a nonessential amino acid that is produced in the body. It is also easily available in many of the foods we eat. For this reason, a food-first approach to getting more tyrosine is usually preferred.
Tyrosine is marketed to relieve stress, ease symptoms of hypothyroidism, and improve brain health, but there is very little scientific evidence to support any of these claims. Speak with a healthcare provider if you are interested in using supplements of any sort.
15 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Attipoe S, Zeno S, Lee C, et al.Tyrosine for mitigating stress and enhancing performance in healthy adult humans, a rapid evidence assessment of the literature.Military Med. 2015 Jul;180(7):754–765. doi:10.7205/MILMED-D-14-00594Mount Sinai.Tyrosine.Young SN.L-tyrosine to alleviate the effects of stress?J Psychiatry Neurosci. 2007;32(3):224.Neri DF, Wiegmann D, Stanny RR, Shappell SA, McCardie A, McKay DL.The effects of tyrosine on cognitive performance during extended wakefulness.Aviat Space Environ Med. 1995;66(4):313-319.O’Brien C, Mahoney C, Tharion WJ, Sils IV, Castellani JW.Dietary tyrosine benefits cognitive and psychomotor performance during body cooling.Physiol Behav. 2007;90(2-3):301-307. doi:10.1016/j.physbeh.2006.09.027Deijen JB, Wientjes CJ, Vullinghs HF, Cloin PA, Langefeld JJ.Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course.Brain Res Bull. 1999;48(2):203-209. doi:10.1016/s0361-9230(98)00163-4Jongkees BJ, Hommel B, Kühn S, Colzato LS.Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands–a review.J Psychiatr Res. 2015;70:50-57. doi:10.1016/j.jpsychires.2015.08.014Remmington T, Smith S.Tyrosine supplementation for phenylketonuria.Cochrane Database Syst Rev. 2021;1(1):CD001507. doi:10.1002/14651858.CD001507.pub4National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances.Proteins and amino acids. Washington (DC): National Academies Press (US); 1989.Boelens Keun JT, Arnoldussen IA, Vriend C, van de Rest O.Dietary approaches to improve efficacy and control side effects of levodopa therapy in Parkinson’s disease: a systematic review.Adv Nutr. 2021;12(6):2265-2287. doi:10.1093/advances/nmab060Flockhart DA.Dietary restrictions and drug interactions with monoamine oxidase inhibitors: an update.J Clin Psychiatry. 2012;73 Suppl 1:17-24. doi:10.4088/JCP.11096su1c.03Palinkas LA, Reedy KR, Smith M, et al.Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence.Int J Circumpolar Health. 2007;66(5):401-417.Zaragoza J, Tinsley G, Urbina S, et al.Effects of acute caffeine, theanine and tyrosine supplementation on mental and physical performance in athletes.J Int Soc Sports Nutr. 2019;16(1):56. doi:10.1186/s12970-019-0326-3Tumilty L, Gregory N, Beckmann M, Thatcher R.No influence of low-, medium-, or high-dose tyrosine on exercise in a warm environment.Med Sci Sports Exerc. 2020;52(6):1404-1413. doi:10.1249/MSS.0000000000002245Sutton EE, Coill MR, Deuster PA.Ingestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance.Int J Sport Nutr Exerc Metab. 2005;15(2):173-185. doi:10.1123/ijsnem.15.2.173
15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Attipoe S, Zeno S, Lee C, et al.Tyrosine for mitigating stress and enhancing performance in healthy adult humans, a rapid evidence assessment of the literature.Military Med. 2015 Jul;180(7):754–765. doi:10.7205/MILMED-D-14-00594Mount Sinai.Tyrosine.Young SN.L-tyrosine to alleviate the effects of stress?J Psychiatry Neurosci. 2007;32(3):224.Neri DF, Wiegmann D, Stanny RR, Shappell SA, McCardie A, McKay DL.The effects of tyrosine on cognitive performance during extended wakefulness.Aviat Space Environ Med. 1995;66(4):313-319.O’Brien C, Mahoney C, Tharion WJ, Sils IV, Castellani JW.Dietary tyrosine benefits cognitive and psychomotor performance during body cooling.Physiol Behav. 2007;90(2-3):301-307. doi:10.1016/j.physbeh.2006.09.027Deijen JB, Wientjes CJ, Vullinghs HF, Cloin PA, Langefeld JJ.Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course.Brain Res Bull. 1999;48(2):203-209. doi:10.1016/s0361-9230(98)00163-4Jongkees BJ, Hommel B, Kühn S, Colzato LS.Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands–a review.J Psychiatr Res. 2015;70:50-57. doi:10.1016/j.jpsychires.2015.08.014Remmington T, Smith S.Tyrosine supplementation for phenylketonuria.Cochrane Database Syst Rev. 2021;1(1):CD001507. doi:10.1002/14651858.CD001507.pub4National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances.Proteins and amino acids. Washington (DC): National Academies Press (US); 1989.Boelens Keun JT, Arnoldussen IA, Vriend C, van de Rest O.Dietary approaches to improve efficacy and control side effects of levodopa therapy in Parkinson’s disease: a systematic review.Adv Nutr. 2021;12(6):2265-2287. doi:10.1093/advances/nmab060Flockhart DA.Dietary restrictions and drug interactions with monoamine oxidase inhibitors: an update.J Clin Psychiatry. 2012;73 Suppl 1:17-24. doi:10.4088/JCP.11096su1c.03Palinkas LA, Reedy KR, Smith M, et al.Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence.Int J Circumpolar Health. 2007;66(5):401-417.Zaragoza J, Tinsley G, Urbina S, et al.Effects of acute caffeine, theanine and tyrosine supplementation on mental and physical performance in athletes.J Int Soc Sports Nutr. 2019;16(1):56. doi:10.1186/s12970-019-0326-3Tumilty L, Gregory N, Beckmann M, Thatcher R.No influence of low-, medium-, or high-dose tyrosine on exercise in a warm environment.Med Sci Sports Exerc. 2020;52(6):1404-1413. doi:10.1249/MSS.0000000000002245Sutton EE, Coill MR, Deuster PA.Ingestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance.Int J Sport Nutr Exerc Metab. 2005;15(2):173-185. doi:10.1123/ijsnem.15.2.173
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Attipoe S, Zeno S, Lee C, et al.Tyrosine for mitigating stress and enhancing performance in healthy adult humans, a rapid evidence assessment of the literature.Military Med. 2015 Jul;180(7):754–765. doi:10.7205/MILMED-D-14-00594Mount Sinai.Tyrosine.Young SN.L-tyrosine to alleviate the effects of stress?J Psychiatry Neurosci. 2007;32(3):224.Neri DF, Wiegmann D, Stanny RR, Shappell SA, McCardie A, McKay DL.The effects of tyrosine on cognitive performance during extended wakefulness.Aviat Space Environ Med. 1995;66(4):313-319.O’Brien C, Mahoney C, Tharion WJ, Sils IV, Castellani JW.Dietary tyrosine benefits cognitive and psychomotor performance during body cooling.Physiol Behav. 2007;90(2-3):301-307. doi:10.1016/j.physbeh.2006.09.027Deijen JB, Wientjes CJ, Vullinghs HF, Cloin PA, Langefeld JJ.Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course.Brain Res Bull. 1999;48(2):203-209. doi:10.1016/s0361-9230(98)00163-4Jongkees BJ, Hommel B, Kühn S, Colzato LS.Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands–a review.J Psychiatr Res. 2015;70:50-57. doi:10.1016/j.jpsychires.2015.08.014Remmington T, Smith S.Tyrosine supplementation for phenylketonuria.Cochrane Database Syst Rev. 2021;1(1):CD001507. doi:10.1002/14651858.CD001507.pub4National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances.Proteins and amino acids. Washington (DC): National Academies Press (US); 1989.Boelens Keun JT, Arnoldussen IA, Vriend C, van de Rest O.Dietary approaches to improve efficacy and control side effects of levodopa therapy in Parkinson’s disease: a systematic review.Adv Nutr. 2021;12(6):2265-2287. doi:10.1093/advances/nmab060Flockhart DA.Dietary restrictions and drug interactions with monoamine oxidase inhibitors: an update.J Clin Psychiatry. 2012;73 Suppl 1:17-24. doi:10.4088/JCP.11096su1c.03Palinkas LA, Reedy KR, Smith M, et al.Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence.Int J Circumpolar Health. 2007;66(5):401-417.Zaragoza J, Tinsley G, Urbina S, et al.Effects of acute caffeine, theanine and tyrosine supplementation on mental and physical performance in athletes.J Int Soc Sports Nutr. 2019;16(1):56. doi:10.1186/s12970-019-0326-3Tumilty L, Gregory N, Beckmann M, Thatcher R.No influence of low-, medium-, or high-dose tyrosine on exercise in a warm environment.Med Sci Sports Exerc. 2020;52(6):1404-1413. doi:10.1249/MSS.0000000000002245Sutton EE, Coill MR, Deuster PA.Ingestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance.Int J Sport Nutr Exerc Metab. 2005;15(2):173-185. doi:10.1123/ijsnem.15.2.173
Attipoe S, Zeno S, Lee C, et al.Tyrosine for mitigating stress and enhancing performance in healthy adult humans, a rapid evidence assessment of the literature.Military Med. 2015 Jul;180(7):754–765. doi:10.7205/MILMED-D-14-00594
Mount Sinai.Tyrosine.
Young SN.L-tyrosine to alleviate the effects of stress?J Psychiatry Neurosci. 2007;32(3):224.
Neri DF, Wiegmann D, Stanny RR, Shappell SA, McCardie A, McKay DL.The effects of tyrosine on cognitive performance during extended wakefulness.Aviat Space Environ Med. 1995;66(4):313-319.
O’Brien C, Mahoney C, Tharion WJ, Sils IV, Castellani JW.Dietary tyrosine benefits cognitive and psychomotor performance during body cooling.Physiol Behav. 2007;90(2-3):301-307. doi:10.1016/j.physbeh.2006.09.027
Deijen JB, Wientjes CJ, Vullinghs HF, Cloin PA, Langefeld JJ.Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course.Brain Res Bull. 1999;48(2):203-209. doi:10.1016/s0361-9230(98)00163-4
Jongkees BJ, Hommel B, Kühn S, Colzato LS.Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands–a review.J Psychiatr Res. 2015;70:50-57. doi:10.1016/j.jpsychires.2015.08.014
Remmington T, Smith S.Tyrosine supplementation for phenylketonuria.Cochrane Database Syst Rev. 2021;1(1):CD001507. doi:10.1002/14651858.CD001507.pub4
National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances.Proteins and amino acids. Washington (DC): National Academies Press (US); 1989.
Boelens Keun JT, Arnoldussen IA, Vriend C, van de Rest O.Dietary approaches to improve efficacy and control side effects of levodopa therapy in Parkinson’s disease: a systematic review.Adv Nutr. 2021;12(6):2265-2287. doi:10.1093/advances/nmab060
Flockhart DA.Dietary restrictions and drug interactions with monoamine oxidase inhibitors: an update.J Clin Psychiatry. 2012;73 Suppl 1:17-24. doi:10.4088/JCP.11096su1c.03
Palinkas LA, Reedy KR, Smith M, et al.Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence.Int J Circumpolar Health. 2007;66(5):401-417.
Zaragoza J, Tinsley G, Urbina S, et al.Effects of acute caffeine, theanine and tyrosine supplementation on mental and physical performance in athletes.J Int Soc Sports Nutr. 2019;16(1):56. doi:10.1186/s12970-019-0326-3
Tumilty L, Gregory N, Beckmann M, Thatcher R.No influence of low-, medium-, or high-dose tyrosine on exercise in a warm environment.Med Sci Sports Exerc. 2020;52(6):1404-1413. doi:10.1249/MSS.0000000000002245
Sutton EE, Coill MR, Deuster PA.Ingestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance.Int J Sport Nutr Exerc Metab. 2005;15(2):173-185. doi:10.1123/ijsnem.15.2.173
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