L Tyrosine Hydroxylase Benefits ADHD Sufferers, Stress & More

HomeL Tyrosine Hydroxylase Benefits ADHD Sufferers, Stress & More

L Tyrosine Hydroxylase Benefits ADHD Sufferers, Stress & More

By John Cornell | | 1 Comment | 21 February, 2018
Optimal brain health has been an issue plenty of supplement brands are trying to tackle. Most are successful due to the effectiveness and  uniqueness of the ingredients. Nootropics are not a new fad and have been popular for a long time. As a matter of fact the amount of online searches are at an all time high shown here by Google Trends.  Any ingredient that can benefit the function of the brain can be useful for people of all ages. In this post we will be discussing the effectiveness of the addition a specific supplement ingredient we have been using often as of alte. That ingredient is l-tyrosine. See why you should include it in your next supplement!
L-tyrosine hydroxylase, an enzyme present in our physiological system is involved in conversion tyrosine hydroxylase image 1.jpgreaction from l-tyrosine to L-DOPA. This L-DOPA act as a neurotransmitter and mood elevator. Thus, supplementation of L-l-tyrosine is a novel evidence-based solution to deal with depression, improve cognition and also promotes other health benefits
L-tyrosine is an amino acid, found in different dietary sources like soy products, animal proteins, dairy products, fresh fruits and vegetables, nuts and seeds. [2]
Yet, the busy work schedule and dependence to packed food often provide an inadequate supply of essential nutrients including l-tyrosine. Additionally, some metabolic disorder and genetic condition also influence l-tyrosine deficiency.
The structural configuration of l-tyrosine allows it to rotate in a plane of polarized light and can provide both  L (anticlockwise movement)  and D form (clockwise movement) of l-tyrosine. Among both the forms, the L form of l-tyrosine is more used for experimental research.
Yet, no significant study result has been found yet to showcase the difference in biological functionality between these two form of l-tyrosine. [3]
l-tyrosine is one of the essential nutritional element which takes the central role in the biosynthesis of bioactive ingredients like thyroxine, catecholamines, and melanin. L-l-tyrosine converts to  L-DOPA through enzymatic reaction conducted by l-tyrosine hydroxylase. [4]

Perspective on the Nutraceutical Market

Before we discuss more health benefits of l-tyrosine hydroxylase supplement, it is imperative to take a look at current nutritional supplementation market. The healthcare industry, as well as the general population, is more attracted towards nutritional supplement products because they want to remain healthy and avoid treatment-related cost burden The clinical management for several health conditions has recently acknowledged the health benefits of nutritional supplement products which have further changed the prescription patterns. Today's' medical doctors and healthcare practitioners prescribe nutritional supplements along with conventional medicines. Study research had also reported the use of vitamins and other nutritional supplements among one-half of adult Americans. [5] According to a data published by FICCI in 2010, the 31 percent market of nutraceuticals are occupied by supplements, and North America after the Asia Pacific, is leading the Nutraceutical market.
Role of  L-tyrosine hydroxylase in Conversion of L-l-tyrosine to L dopa
l-tyrosine hydroxylase enzyme can control dopamine and other catecholamines availability in the brain. The rate of release of dopamine is controlled by l-tyrosine hydroxylase. The activity of l-tyrosine hydroxylase is increased during stressful situation or reaction against emotional hit, and further increase the conversion of l-tyrosine to dopamine. So, dopamine synthesis in the central nervous system is controlled by l-tyrosine hydroxylase enzymatic activity. [4]

L-tyrosine Deficiency 

L-tyrosine hydroxylase deficiency is related to an altered genetic mutation that occurs in TH gene. This condition is considered as an inherited autosomal condition. It is transferred from affected parents to their children. The condition is treated by administering dopamine in the form of Levo-dopa medication. So, there is no connection with a dietary deficiency. [6]
Moreover, according to the research publication, the intake of adequate vitamin C (ascorbic acid) during embryonic brain development stage can improve the neurotransmitter synthesis in brain and l-tyrosine hydroxylase expression. [7] So, pregnant women should take adequate amount of citrus food for the proper functioning of l-tyrosine hydroxylase.   

Can L-tyrosine Cause Over-Activity of the Brain?

It has been observed that the increased dose of l-tyrosine cannot improve the production of dopamine. The dopamine and other catecholamine synthesis are regulated by the enzymatic activity of l-tyrosine hydroxylase, which induces metabolic functioning of l-tyrosine and converts them into next metabolite, i.e. L-DOPA. Therefore,  the rate of dopamine production is directly dependent upon availability and functionality of the l-tyrosine hydroxylase. Hence the dose escalation of L-dopa does not cause over-stimulation of brain functioning.

Health Benefits of L-tyrosine

Role of L-tyrosine in Stress-Induced Memory Loss
The l-tyrosine supplementation can be expected to play as a memory booster by modifying brain functioning. [8] However, research investigation showed that administration of L l-tyrosine supplement can prevent the stress induce memory loss by improving noradrenalin concentration in the hippocampus. [9]
 tyrosine hydroxylase image 4.jpg
Neuronal Disease Preventive and Curative Effect
It has been observed that deficiency of dopamine and other catecholamines, such as adrenalin and noradrenalin causes different neuronal disorders like Parkinson's disease and also induces depression. [10] Supplementation of L-l-tyrosine is effective to control several neuronal conditions by improving the availability of dopamine. A small-scale clinical study conducted on patients having Parkinson's disease has shown that the group who received L-l-tyrosine with conventional medicinal therapy (probenecid) had significant improvement in the increased homovanillic acid level, which is one of the major metabolites of dopamine. This result indicates that l-tyrosine can improve the dopamine turnover in the brain. [11]
Research evidence also supports that supplementation of l-tyrosine can improve mental clouding, mood disorder, and depression. [12]
L-tyrosine Acts as an Anti-stress Regimen
The catecholamines, as like adrenaline and noradrenaline have an anti-stress effect and preserve the brain workability in stressful conditions. Researchers reported that  L-l-tyrosine supplementation can act as building blocks and retain the catecholamines functioning by preventing their depletion for prolong period and prevent mental stress. In this condition, the upholding of the catecholamines functioning through L-l-tyrosine supply is referred as 'safety buffer'. [9]
Continuous stressful work culture induces fatigue, which provides a negative impact on mental concentration. l-tyrosine supplementation reduces the fatigue syndrome and simultaneously improve concentration.   [13]
L-tyrosine for Negative Environmental Conditions
The negative environmental condition, like excessive cold exposure or night-shift duty, often decreases brain functioning due to the reduction of noradrenalin level in the brain. Supplementing L-l-tyrosine can help to maintain the noradrenalin level in the brain. In addition, it also encourages to continue the physical performance at cold, stress, high altitude zone, and extended alertness. This advantage of l-tyrosine is often beneficial for armed forces during their continual operational performances. [9]
A double-blind clinical trial result performed in exposure to cold and oxygen deficit condition for four and half hour period reported that l-tyrosine supplementation prevents disturbed mood-related symptoms, and improve physical performance with great responsiveness. This can be achieved due to preventing catecholamine depletion in the brain, adequate supply of dopamine and other neurotransmitters.  [14]
In another study, it has been observed that often in tasks involving vigilance at night, breaks the alertness due to lack of sleep which further induces stress build-up. A placebo-controlled, double-blind study showed that administration of l-tyrosine had ameliorated the mental functioning and wakefulness during the strict vigilance job performance and that lasted for three hours.   [15]
L-tyrosine Could Improve ADHD
ADHD or the attention deficit hyperactivity disorder is considered as a mental disorder. A study performed on pediatric patients who are suffering from ADHD by providing l-tyrosine supplementation in combination with conventional drug and other nutrients like vitamins, minerals, and other bioactive natural ingredients. The study results showed the improvement of the symptom of the participants under the regimen
L-tyrosine Could Improve Thyroid Hormone Level
Both T3 and T4 are two important thyroid hormone, that performs two major physiological functioning in the body, including neuronal development and metabolic functioning. Both of these are important for mental and physical functioning. [17] An animal study showed that administration of combination dietary supplement of phenylalanine-l-tyrosine improves the thyroid hormone level in blood plasma. [18]
L-tyrosine Could Help Prevent Cardiac Disease
Increased blood pressure or hypertensive condition is often a major cause of promoting cardiac disease. l-tyrosine supplementation can reduce systolic blood pressure. Thus, it assists to control hypertension and prevent cardiac disease. [13]
L-tyrosine & Skin Condition
Melanin is the natural pigment responsible for skin coloration. Vitiligo is a skin disorder in which natural melanin synthesis in the skin is reduced. Research evidence found that L-tyrosine supplementation can ease melanogenesis. [4]

With benefits able to satisfy the nutritional needs of many different issues at once this supplement ingredient would be great to include in your next formula. Whether you are a supplement pro or a novice in the game the team here at ABH Pharma can assist you from start to finish! Already have a formula in mind? Click below and send it over to receive a free quote!
Provide Your Formula Here To Expedite the Quote Process


  1. http://apps.who.int/iris/bitstream/10665/254610/1/WHO-MSD-MER-2017.2-eng.pdf
  2. https://www.umm.edu/health/medical/altmed/supplement/l-tyrosine
  3. http://www.differencebetween.com/difference-between-l-l-tyrosine-and-vs-l-tyrosine/
  4. http://www.tandfonline.com/doi/abs/10.1080/13590849861934
  5. https://www.researchgate.net/publication/268293942_NUTRACEUTICALS_AND_THE_FUTURE_OF_MEDICAL_SCIENCE
  6. https://rarediseases.info.nih.gov/diseases/1902/l-tyrosine--deficiency
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3849618/
  8. https://www.ncbi.nlm.nih.gov/pubmed/10837313
  9. https://examine.com/supplements/l-l-tyrosine/
  10. http://www.tandfonline.com/doi/abs/10.1080/13590849861934
  11. https://www.ncbi.nlm.nih.gov/pubmed/6175872

John Cornell

Written by John Cornell

John is the vice president of business development here at ABH Pharma. John has years of experience working with both Supplement Brands & Manufacturers, giving him great insider knowledge of operations & sales methodology that works within this industry. John is constantly reviewing new product trends and listening to feedback from industry leaders to better his clients. He is also particularly intuitive when it comes to the formulation of supplements.

amazon tools & tricks e-book

Subscribe to Email Updates