Tyrosine is a popular supplement among people who want to reduce fatigue. It belongs to endogenous amino acids. Our body can produce it, but not in the right amount. If we cannot provide it with food, we should think about supplementation. Tyrosine is involved in the construction of muscle proteins. It is important in the synthesis of neurotransmitters, i.e. dopamine, adrenaline and norepinephrine. Tyrosine reduces mental fatigue, improves resistance to stress and reduce fatigue after training. It also reduces mental fatigue and improves resistance to stress. The human body can produce it itself, however, in order to achieve this, the correct amount of phenylalanine, which is also an amino acid, is needed. It improves concentrations during intensive work and during slimming. Helpful during diet due to the properties of reducing appetite. It protects the body against the harmful effects of UV radiation. Thanks to the stimulation of melatonin production, it affects the skin and hair color. Participates in the synthesis of thyroid hormones. Thyroid is responsible for the regulation of metabolic changes that occur in the human body. It is recommended for people practicing sports, having a significant overweight or obesity, using tanning beds, struggling with stress and in need of strengthening the body. Not recommended for people suffering from melanoma and high levels of dopamine.