L-Tyrosine
Amino Acid ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Precursor to dopamine, norepinephrine, and epinephrine. Excellent for maintaining cognitive performance under stress, sleep deprivation, or multi-tasking demands.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
L-Tyrosine is an amino acid most often used for focus under stress, dopamine support, cognitive resilience. NutriStack rates the overall evidence as moderate. A typical adult dose is 500–2,000 mg daily, commonly taken as l-tyrosine (better absorbed than nalt). This profile indexes 17 sources.
The bottom line
Evidence rating moderate. Most-documented uses: focus under stress, dopamine support, cognitive resilience. 17 sources indexed (1989–2026), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Hydroxylated by tyrosine hydroxylase (rate-limiting step) to L-DOPA, then converted to dopamine by aromatic L-amino acid decarboxylase. Dopamine is further converted to norepinephrine and epinephrine. Replenishes catecholamine stores depleted by stress.14,1
Dosing & protocol.
Take on empty stomach 30 min before meals for best brain uptake; competes with other amino acids1,3
What it actually costs.
Real-world pricing across three quality tiers. Assumes L-Tyrosine.
Assumes 500-2,000 mg/day. Vendor basis: NOW/iHerb, Vitacost, BulkSupplements powder, and Amazon marketplace; NALT blends are not used for the base tier. Updated 2026-05-28.
The same dose, as food.
How much you'd eat to match a supplemental dose.
Whole protein sources are practical tyrosine sources.
Full safety detail.
Side effects
- Headache
- Nausea
- Heartburn
- Insomnia if taken late
Contraindications
- MAO inhibitors
- Hyperthyroidism
- Melanoma
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
2- 1The effect of tyrosine supplementation on whole-body endurance performance in physically active population: A systematic review and meta-analysis including GRADE qualificationPMIDSolon-Júnior LJF, Boullosa Alvarez DA, Martinez Gonzalez B et al. · Journal of sports sciences · 2023
Solon-Júnior LJF, Boullosa Alvarez DA, Martinez Gonzalez B et al.. The effect of tyrosine supplementation on whole-body endurance performance in physically active population: A systematic review and meta-analysis including GRADE qualification. Journal of sports sciences. 2023
- 2Tyrosine for the treatment of phenylketonuria and as a cognitive enhancer in healthy individuals: a systematic reviewSource linkedPMIDJongkees BJ, Hommel B, Kuhn S, Colzato LS · Neuroenhancement · 2015
Randomized controlled trials
6- 3On the effects of tyrosine supplementation on interference control in a randomized, double-blind placebo-control trialPMIDStock AK, Colzato L, Beste C · European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology · 2018
Stock AK, Colzato L, Beste C. On the effects of tyrosine supplementation on interference control in a randomized, double-blind placebo-control trial. European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology. 2018
- 4Effects of l-Tyrosine on working memory and inhibitory control are determined by DRD2 genotypes: A randomized controlled trialPMIDColzato LS, Steenbergen L, Sellaro R et al. · Cortex; a journal devoted to the study of the nervous system and behavior · 2016
Colzato LS, Steenbergen L, Sellaro R et al.. Effects of l-Tyrosine on working memory and inhibitory control are determined by DRD2 genotypes: A randomized controlled trial. Cortex; a journal devoted to the study of the nervous system and behavior. 2016
- 5Tyrosine improves working memory in a multitasking environmentSource linkedPMIDColzato LS, Jongkees BJ, Sellaro R, Hommel B · Pharmacol Biochem Behav · 2013
- 6Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training coursePMIDDeijen JB et al. · Brain Res Bull · 1999
Tyrosine supplementation improved cognitive task performance and reduced blood pressure in military cadets after demanding combat training
- 7Tyrosine reverses a cold-induced working memory deficit in humansPMIDShurtleff D et al. · Pharmacol Biochem Behav · 1994
Tyrosine significantly improved matching accuracy at the longest delay interval most affected by cold exposure
- 8Treatment of narcolepsy with L-tyrosine: double-blind placebo-controlled trialPMIDElwes RD, Crewes H, Chesterman LP et al. · Lancet (London, England) · 1989
Elwes RD, Crewes H, Chesterman LP et al.. Treatment of narcolepsy with L-tyrosine: double-blind placebo-controlled trial. Lancet (London, England). 1989
Reviews & position papers
7- 9O-(2-[(18)F]fluoroethyl)-L-tyrosine-PET-guided versus contrast-enhanced T1-weighted MRI-guided re-irradiation in patients with recurrent glioblastoma (GLIAA/NOA-10 ARO2013-01): a multicentre, open-label, randomised trialPMIDGrosu AL, Weber WA, Graf E et al. · The Lancet. Oncology · 2026
Grosu AL, Weber WA, Graf E et al.. O-(2-[(18)F]fluoroethyl)-L-tyrosine-PET-guided versus contrast-enhanced T1-weighted MRI-guided re-irradiation in patients with recurrent glioblastoma (GLIAA/NOA-10 ARO2013-01): a multicentre, open-label, randomised trial. The Lancet. Oncology. 2026
- 10Amino acid supplementation in mitochondrial aminoacyl-tRNA synthetase defects: two case reports of tyrosine supplementation in YARS2-associated disease and a review of the literaturePMIDFerrera G, Segre G, Lamantea E et al. · Frontiers in pediatrics · 2025
Ferrera G, Segre G, Lamantea E et al.. Amino acid supplementation in mitochondrial aminoacyl-tRNA synthetase defects: two case reports of tyrosine supplementation in YARS2-associated disease and a review of the literature. Frontiers in pediatrics. 2025
- 11Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands--A reviewPMIDJongkees BJ et al. · J Psychiatr Res · 2015
Tyrosine acutely counteracts decrements in working memory and information processing induced by demanding conditions like extreme weather or cognitive load
- 12Tyrosine for Mitigating Stress and Enhancing Performance in Healthy Adult Humans, a Rapid Evidence Assessment of the LiteraturePMIDAttipoe S et al. · J Mil Med · 2015
Weak recommendation in favor of tyrosine for cognitive stress; all 10 RCTs and 4 controlled trials showed positive effect on cognition under stress
- 13LncRNA NALT interaction with NOTCH1 promoted cell proliferation in pediatric T cell acute lymphoblastic leukemiaPMIDWang Y, Wu P, Lin R et al. · Scientific reports · 2015
Wang Y, Wu P, Lin R et al.. LncRNA NALT interaction with NOTCH1 promoted cell proliferation in pediatric T cell acute lymphoblastic leukemia. Scientific reports. 2015
- 14Tyrosine, phenylalanine, and catecholamine synthesis and function in the brainPMIDFernstrom JD, Fernstrom MH · J Nutr · 2007
Tyrosine hydroxylase is the rate-limiting enzyme converting tyrosine to L-DOPA, then to dopamine, norepinephrine, and epinephrine
- 15Review of L-tyrosine confirming its safe human use as an adjuvantPMIDHoffer LJ · J Food Biochem · 2002
L-tyrosine appears safe with no signs of toxicity or genotoxicity in preclinical studies; well tolerated in clinical trials
Reference material
2- 16McAllister MJ, Martaindale MH, Dillard CC et al.. Impact of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality based active shooter training drill. Stress (Amsterdam, Netherlands). 2024Source linkedPMID
- 17Blachier F, Andriamihaja M. Effects of the L-tyrosine-derived bacterial metabolite p-cresol on colonic and peripheral cells. Amino acids. 2022Source linkedPMID
Common questions.
Quick answers about L-Tyrosine, drawn from the data on this page.
What is L-Tyrosine?
Precursor to dopamine, norepinephrine, and epinephrine. Excellent for maintaining cognitive performance under stress, sleep deprivation, or multi-tasking demands.
What is L-Tyrosine used for?
Commonly cited benefits of L-Tyrosine include: Focus under stress; Dopamine support; Cognitive resilience; Mood support; Thyroid hormone synthesis. NutriStack rates the overall evidence as moderate.
What is a typical dose of L-Tyrosine?
A typical adult dose of L-Tyrosine is 500–2,000 mg daily. The commonly recommended form is L-tyrosine (better absorbed than NALT). These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of L-Tyrosine?
Reported side effects include headache, nausea, heartburn, insomnia if taken late. This is educational information; check with a healthcare professional before use.
How strong is the evidence for L-Tyrosine?
NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
L-Tyrosine in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.