100 CAPS | 500 MG Product No. 00148

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L-Tyrosine has many and varied functions. It is needed to make epinephrine, norepinephrine and dopamine; all of which work to regulate mood. It aids in the production of melanin, in the regulation of the adrenal, thyroid and pituitary glands, and is involved in the synthesis of enkephalins, the body’s natural pain relievers. L-Tyrosine should not be used with MAO inhibitors. *

  • Benefits overall metabolism*
  • Provides building block for energizing neurotransmitters*
  • Promotes focus and mental clarity*


*These statements have not been evaluated by the Food & Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.



Product Code: 00148           Capsules per Bottle: 100


Each size 00 vegetarian capsule contains:


Vitamin B-6 (as Pyridoxine HCI)

10 mg


500 mg

  Other ingredients: L-leucine.


Description: L-Tyrosine is an amino acid with many varied functions. The metabolism of tyrosine is a precursor for the production of catecholamines (epinephrine, norepinephrine and dopamine), all of which regulate mood, focus and cognitive function. L-Tyrosine is converted into the compound L-DOPA by tyrosine hydroxylase. L-DOPA is then decarboxylated via aromatic L-amino acid decarboxylase into dopamine, which can be oxidized into norepinepherine by enzyme dopamine-beta-hydroxylase and then converted to epinephrine via phenylethanolamine-N-methyl-transferase [1].



Uses:  Human studies have shown that supplementation of tyrosine increases plasma tyrosine and enhances brain dopamine production [2]. L-Tyrosine is a precursor for the production of both dopamine and norepinephrine with mounting evidence to suggest that tyrosine supplementation may improve cognitive flexibility and counteract or reverse cognitive decline through the rescue of neurotransmitter function [3,4]. Studies are currently being conducted to determine cases in which this effect is most pronounced, but at present, data indicate significant beneficial effects of tyrosine on cognition in acutely stressful situations such as extreme cold, high altitude, and sleep deprivation [3,4]. These data and others have been gathered to support a therapeutic use for tyrosine to reduce neurological decline in elderly patients with dementia. As dementia progresses, catecholamine levels decrease, and catecholamines have an antioxidant effect in the brain, which may in fact be neuroprotective [5].


On a related note, L-tyrosine is also a component of enkephalins (or endorphins), natural pain relievers that activate pathways resulting in simultaneous dopamine release and locomotor activation [6]. The role of L-tyrosine is essential to the hypothalamo-pituitary-adrenocortical (HPA) axis, which is the primary modulator of the adrenal glucocorticoid stress response, as well as regulation of the adrenal, thyroid and pituitary glands [7].


Additionally, L-tyrosine is necessary to the production of melanin, a biological pigment and polymer with myriad beneficial functions in the body, some structural, some physiological [8].



Source Materials: Pyridoxine HCl is made by chemical synthesis. L-tyrosine is derived from hydrolyzed corn protein. L-leucine is made by fermentation. Cellulose for capsules is derived from softwood tree pulp. All ingredients are vegan and non-GMO.


Allergens:  According to information provided by our suppliers, these capsules are free of the eight major allergens as identified by the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA): Wheat (gluten), eggs, milk, soybeans, shellfish, fish, peanuts, tree nuts.


Recommendations: Use as directed by a healthcare professional.


Precautions: L-Tyrosine should not be used with MAO inhibitors. Pregnant or lactating women and individuals taking prescription medications should consult with a healthcare professional before taking any supplement.



  1. Nakashima A, et al. Role of N-terminus of tyrosine hydroxylase in the biosynthesis of catecholamines. J Neural Transm. (2009)
  2. Colzato, Lorenza S., et al. "Eating to stop: tyrosine supplementation enhances inhibitory control but not response execution." Neuropsychologia 62 (2014): 398-402.
  3. Jongkees, Bryant J., et al. "Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands—a review." Journal of psychiatric research 70 (2015): 50-57.
  4. Neri DF, et al. The effects of tyrosine on cognitive performance during extended wakefulness. Aviat Space Environ Med. (1995)
  5. Jodko K, Litwinienko G. Oxidative stress in the neurodegenerative diseases--potential antioxidant activity of catecholamines. Postepy Biochem. (2010)
  6. Sesack, S. R., and V. M. Pickel. "Dual ultrastructural localization of enkephalin and tyrosine hydroxylase immunoreactivity in the rat ventral tegmental area: multiple substrates for opiate-dopamine interactions." Journal of Neuroscience 12.4 (1992): 1335-1350.
  7. Herman, James P., Chantai M-F. Prewitt, and William E. Cullinan. "Neuronal circuit regulation of the hypothalamo-pituitary-adrenocortical stress axis." Critical Reviews™ in Neurobiology 10.3-4 (1996).
  8. Riley, P. A. "Melanin." The international journal of biochemistry & cell biology 29.11 (1997): 1235-1239.



These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


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