In a controlled study on 38 volunteers the effect of 250 mcg/Kg N,N-Dimethyltryptamine (DMT) i.m. were assessed. 26 subjects received DMT and 12 placebo. The altered states of consciousness and the somatic changes were measured by several questionnaires administrered after the experiment. In spite of the low dose as compared to previous studies significant differences to placebo were found in the following syndromes of altered states of consciousness: visual hallucinations resp. illusions, impairment of memory and attention, change of body image, depersonalization syndrome, derealization syndrome, euphoric state, anxious-depressive state and delusion. The somatic side effects were mainly subjective repiratory troubles, dizziness and weakness.