Tremors, restlessness, nausea, palpitations and cardiac arrhythmias, sleep disturbances, headaches, nervousness, irritability, loss of appetite, aggressive behaviour and, in combination with alcohol, danger of alcohol poisoning. At high doses: hallucinations, circulatory failure, strokes as well as kidney, liver and heart failure and states of deep unconsciousness. An often underestimated danger is the rise in body temperature, which can lead to dehydration of the body. In high doses, acute amphetamine psychosis can occur. Signs of this are hallucinations in the form of colour spots and with features of schizophrenia. The risk of such an acute mental disorder increases with consumption over several days and/or if high doses are taken and food intake and sleep are neglected over a longer period of time. Such an experience usually normalises after sufficient sleep. During and after coming down: extreme need for sleep, exhaustion, strong feeling of hunger,depressive mood, irritability, etc.
There is a risk of dependence with psychological symptoms, especially if use takes on a (performance-enhancing) function in everyday life (e.g. at work) or physical/psychological exhaustion is combated with amphetamine. Frequent use of amphetamine not infrequently leads to physical deficiency symptoms (e.g. calcium deficiency, which can lead to bone and dental problems) and to psychological problems such as dejection or listlessness. Regular and high-dose use can lead to constant restlessness (but also persistent fatigue), sleep and circulatory disorders, and anxiety disorders, up to and including persistent amphetamine psychosis with paranoid delusions. In addition, high blood pressure, cardiac arrhythmias, weight loss, skin inflammation ("speed pimples"), stomach problems as well as liver and kidney damage and convulsions are possible. Snorting damages the nasal mucous membranes and the nasal septum, and swallowing damages the stomach mucous membranes. Chronic consumption also favors brain hemorrhages and strokes with sudden paralysis.