L–Tyrosine

L-tyrosine is a non-essential fatty acid, very poorly soluble in water, which plays an important role in the production of the neurotransmitters dopamine and norepinephrine. Tyrosine is also a precursor of thyroxine and triiodothyronine, as well as the pigment melanin.

First of all: please don’t self-medicate! If this amino acid is used incorrectly, it can cause sleep problems, among other issues.                     

HO-p-Ph-CH2-CH(NH2)-COOH

What it does in the body                                                                                                                 

In the liver, phenylalanine is converted into the non-essential amino acid tyrosine. In this way, it is indirectly involved in the synthesis of adrenaline, thyroid hormones, and melanin. Both amino acids influence the metabolism of neurotransmitters — and therefore mood and mental performance. Tyrosine is needed in the body for the proper functioning of the adrenal glands, the thyroid and the pituitary gland, as well as for the formation of red and white blood cells. In addition, via the enzyme tyrosinase, tyrosine helps to build melanin — the pigment responsible for skin and hair colour. Like phenylalanine, tyrosine is also a precursor involved in the production of L-Dopa, dopamine, noradrenaline and adrenaline. The body’s need for tyrosine can also be met through phenylalanine. Because tyrosine is produced during the conversion process from phenylalanine on the pathway towards noradrenaline, it is not considered an essential amino acid. Foods particularly rich in tyrosine include casein (milk protein), peas, beans and nuts. Tyrosine is said to have a mood-lifting effect and may also help reduce appetite.

Taking tyrosine is often said to stimulate a stronger release of growth hormone (HGH) and — as a so-called “brain nutrient” — to support improved mental performance.
Tyrosine plays a key role in stimulating and regulating brain activity. A deficiency may hinder the brain’s ability to produce enough noradrenaline, which in turn can contribute to depressive symptoms. For that reason, tyrosine is commonly used with the aim of keeping depression and anxiety under control.
Effects
Tyrosine can make you feel — and stay — more awake, and it may stimulate both physical and mental activity.                                                                  In line with this, these amino acids are sometimes used in the context of depression, PMS (premenstrual syndrome), reduced sexual desire, excessive appetite, multiple sclerosis, Parkinson’s disease, pain, stress, and hyperactivity in children.
There are known interactions between phenylalanine and tyrosine and certain antidepressants. For the same reason, they should not be taken if dopamine levels are already high, or in cases of schizophrenia.

Noradrenaline influences our moods and our memory. A higher level of L-tyrosine is therefore associated with physical and mental alertness, and a sense of vitality. These qualities make tyrosine interesting for anyone who’s firmly in working life and expected to perform every day. A raised L-tyrosine level is said to increase physical and mental stamina and help prevent rapid fatigue or exhaustion. It is said to help prevent these states, as well as the exhaustion and irritability that often accompany withdrawal from addictive substances — tobacco, alcohol, and the like — and to make the process of quitting easier. Tyrosine is also described as an excellent support for dieting. In the adrenal medulla, the hormones adrenaline and noradrenaline are formed from L-tyrosine and, when required, released directly into the bloodstream. It also contributes to the production of the thyroid hormones triiodothyronine (T3) and thyroxine (T4) in the colloid of the thyroid gland. The amino acid tyrosine is a metabolic precursor of the neurotransmitters dopamine and noradrenaline, which may be produced in lower amounts under conditions of stress and overwork.

By replenishing noradrenaline stores through tyrosine supplementation, mental performance, alertness and mood may improve. Some forms of depression — especially exhaustion-related depression — can become more manageable and give way to a feeling of satisfaction. In this sense, tyrosine is often described as acting faster than phenylalanine, which first has to be converted in the liver before it can exert an effect in the brain.

A smaller proportion of the noradrenaline produced is also converted into adrenaline. This can lead to rises in blood pressure. For that reason, if someone has high blood pressure, use should be approached cautiously and introduced gradually.
Tyrosine is also a precursor of two thyroid hormones, which is why it may be used to stimulate the body’s heat production — increasing fat burning and supporting weight loss.
Warning: As a precaution, cancer patients should not take tyrosine, because some cancers — such as melanomas — can use tyrosine to support their growth.

Tyrosine is an aromatic amino acid. It differs from phenylalanine by a hydroxyl group on the phenyl ring. This makes it significantly more polar than phenylalanine — and also than tryptophan. Beyond that, the hydroxyl group gives tyrosine a higher reactivity than amino acids with more inert side chains.
Tyrosine is the starting substance for the biosynthesis of melanin.
Within the body, tyrosine occurs as a breakdown product of proteins.
The conversion process from tyrosine to melanin takes place under the influence of sunlight.
The intensity of a tan depends on the amount of melanin in the skin. The more tyrosine, the darker the colour.
Naturally, this process can also be triggered under artificial sunlight from a sunbed. After all, you can achieve a lovely brown skin tone in a solarium too.

Source: https://www.diegesundheitsseite.de/versorgung/aminosuren/ltyrosin