The answer is ‘it activates serotonin receptors in the brain stem, hypothalamus, and limbic system, increasing the concentration of serotonin.’ The drug enhances dopamine D2 receptor protomer recognition and signaling of D2–5-HT2A receptor complexes, which may contribute to its psychotic effects. LSD was found to stay bound to both the 5-HT2A and 5-HT2B receptors for an exceptionally long amount of time, which may be responsible for its long duration of action in spite of its relatively short terminal half-life.