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Tyrosine (L-Tyrosine) 250 mg



R 220.00

We've curated every product in our I DO | Nutrition shop based on their nutrigenomic properties and leading manufacturing standards. Nutrigenomics is the study of food and nutrients as one of the most important environmental modifiers of gene expression. A personalised protocol based on your unique DNA, biochemistry and symptoms can help you create optimal wellness and prevent many chronic lifestyle-related diseases. This is called 'personalised scientific wellness'.

120 capsules

An amino acid which is a building block for several important mood-enhancing brain chemicals (neurotransmitters) such as serotonin, dopamine, and noradrenaline. Tyrosine is a precursor of thyroid hormones and it also assists in the function of the glands responsible for making and regulating hormones, including the adrenal, thyroid and pituitary glands. Tyrosine is, therefore, useful to improve thyroid function, for stress management, to increase low energy levels, for increased alertness, as an appetite suppressant, and to increase sexual desire.

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Pharmacological Action

L-Tyrosine is a non-essential amino acid that the body synthesises from L-Phenylalanine. For people with phenylketonuria who cannot synthesize L-Tyrosine from L-Phenylalanine, L-Tyrosine is an essential amino acid. Tyrosine is a precursor of thyroxine and melatonin. It is also a precursor in the synthesis of catecholamines, norepinephrine, epinephrine and dopamine. L-Tyrosine is classified as a large neuronal amino acid (LNAA) and competes with other LNAA’s, such as L-Tryptophan, to get in the brain. It has been suggested that the brain cannot produce enough tyrosine from L-Phenylalanine under stress. Catecholamines like epinephrine, norepinephrine and dopamine that are synthesised from L-Tyrosine can become depleted through stress. Increasing the availability of L-Tyrosine in the brain during times of stress can reduce the damaging effects of stress. Studies have indicated that supplemental L-Tyrosine may improve memory, performance and learning under stress.

Product Composition

Each capsule contains the following active ingredient:

L-Tyrosine 250mg

Inactive ingredients: Magnesium stearate, microcrystalline cellulose, silicon dioxide and talc.

Suitable for vegetarians.

Dosage Directions

To enhance thyroid function:
Adults: Take 2 capsules twice daily.
Children 7 – 12 years: Half the adult dose.

For mood enhancing effects and for energy:
Adults: Take 4 capsules twice daily.
Children 7 – 12 years: Half the adult dose.

For increased mental alertness:
Adults: Take 4-8 capsules twice daily.
Children 7 – 12 years: Half the adult dose.

For improved sexual desire:
Adults: Take 4-8 capsules twice daily.

Take on an empty stomach (30 minutes or more before meals). Because L-Tyrosine can cause insomnia, the best times to take it are in the morning and the second dose not later than 4pm.

Product Warnings

Do not use this product if you are hypersensitive (allergic) to any of the ingredients. If you are on any medication or suffering from any medical condition, it is advisable to seek medical advice before starting any new medicine, supplement or remedy. Do not exceed recommended dosages unless on the advice of a healthcare practitioner. This medicine has not been evaluated by the Medicines Control Council. This medicine is not intended to diagnose, treat, cure or prevent any disease. Health supplements are intended only to complement health or supplement the diet.

Side Effects

The following side effects have been reported: nausea, headache, heartburn and joint pain.


Hyperthyroidism, Graves’ Disease: L-Tyrosine might exacerbate these conditions and should be avoided in individuals suffering from these conditions.
Melanoma and Glioblastoma multiforme: These tumours metabolise L-Tyrosine as part of their growth.
Schizophrenia: Individuals suffering from schizophrenia that have elevated dopamine levels should avoid taking tyrosine.


Levodopa: L-Tyrosine may decrease the effectiveness of L-Dopa, as they both compete for absorption in the proximal duodenum, doses of tyrosine and levodopa should be separated by 2 hours.
Thyroid Hormone: L-Tyrosine may have additive effects with thyroid hormone medications as tyrosine is a precursor of thyroid hormone.

Pregnancy and Breastfeeding

Safety during pregnancy and breastfeeding has not been established.

Storage Instructions

Store in a cool dry place below 25°C. Keep out of reach of children.


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