The activation of 5-HT2A receptors by the binding of some ligands produces several altered states of consciousness in humans. The knowledge of the manner a hallucinogen interacts with this receptor should be the first step to know how these chemicals transfer information to produce the final biological effect(s). Here, we present the results of a docking study of some hallucinogens (LSD, mescaline, DMT, 25I-NBOMe and others), to a recent model of the 5- HT2A receptor. The rigid and flexible residues approaches were employed. The best approach is to allow conformational flexibility to the residues of the binding site. The Val-156 residue appears to be common to all flexible docking results and all molecules interact with the transmembrane 3 helix. The other interactions are particular to each molecule.
