text: The pharmacophore model for TRPV1 antagonists consists of three essential features: a hydrogen-bond acceptor, a hydrogen-bond donor, and a ring feature. In addition, the TRPV1 antagonists have been superimposed in such a way that they could fit in the volume of the TRPV1 pore. When the homology model is considered, appropriate interaction sites are found in the receptor pore. The hydrogen-bond acceptor on the ligand is proposed to interact with Tyr 667 (helix S6) on the receptor as a hydrogen-bond donor, and the hydrogen-bond donor on the ligand is proposed to interact with Tyr 667 on the opposite monomer of the tetramer on the receptor as a hydrogen-bond acceptor. The ring feature of the pharmacophore is proposed to fit in the hydrophobic space formed by the aromatic rings of the four Tyr 667 residues of the four monomers. Consistent with the critical role played by Tyr 667 in the interaction with key elements of the TPRV1 antagonist pharmacophore, site-directed mutagenesis studies have shown that exchanging this tyrosine for alanine in the rat TRPV1 receptor abolishes functional activity of TRPV1. The lipophilic end in antagonist is varied in character and volume and interacts with the lower end of transmembrane helices S5 and S6. Because the intracellular ends of these helices extend past the membrane, they are likely to be flexible and may be part of the channel opening and closing process. The combined use of a pharmacophore model, assembled from highly optimized TRPV1 antagonists, with a homology model of the protein has enhanced understanding of the observed structure–activity relationships of many series of current TRPV1 antagonists, and should be useful in the discovery of new classes of antagonists.