Amphetamines are a group of psychoactive synthetic substances, derivatives of phenylalkylamine, a pharmacological analogue of adrenaline and noradrenaline hormones, which are strong stimulants of the central nervous system. The mechanism of action of amphetamines is associated with activation of adrenergic transmission, an increase in the release of norepinephrine and dopamine in synapses and inhibition of their re-uptake, stimulation of peripheral adrenergic receptors. Amphetamines are able to easily penetrate the blood-brain barrier and have a powerful effect on the central nervous system: they cause vasoconstriction, increased blood pressure, increased heartbeats, dilated pupils, and excessive sweating. The nature of their effects, duration and severity of symptoms depends on the effectiveness of the drug and on the dose. Psychological dependence arises very quickly. Abstinence syndrome occurs 9 hours to 4 days after drug withdrawal and can persist for up to 1-10 weeks. The half-life period from the blood of amphetamines and their metabolites, on average, is 8-12 hours (depending on the dose, nutrition and substance - from 6 to 34 hours). The detection of amphetamines in the test sample confirms the use of amphetamines in the previous 8-12 hours in the study of blood.