The tachykinin receptor 1 (TACR1) also known as neurokinin 1 receptor (NK1R) or substance P receptor (SPR) is a G protein coupled receptor found in the central nervous system and peripheral nervous system. The endogenous ligand for this receptor is Substance P, although it has some affinity for other tachykinins. The protein is the product of the TACR1 gene. This receptor is considered an attractive drug target, particularly with regards to potential analgesics and anti-depressants. It is also a potential treatment for alcoholism and opioid addiction. In addition, it has been identified as a candidate in the etiology of bipolar disorder. Finally NK1R antagonists may also have a role as novel antiemetics and hypnotics.