Depending upon the subject, androstenone can have an unpleasant, sweaty, urinous smell, a woody smell, or even a pleasant floral smell.[3][7][8]
There are two different genotypes that allow an individual to smell androstenone. The first genotype, which consists of two fully functional copies of the gene, is the RT/RT allele, and the second is the RT/WM allele.[citation needed] The OR7D4 receptor[4] has two non-synonymous single nucleotide polymorphisms,[9] which cause the gene to have two amino acid substitutions, which in turn cause the receptor to act differently. Those in possession of the two proper genes, (RT/RT) for OR7D4 tend to describe the odor for the steroid as the odor of stale urine. Those with only one gene (RT/WM) typically described the odor as weak or were not able to detect it. They can also find the smell 'pleasant', 'sweet' or 'similar to vanilla'.[10]
In small amounts, the odor is hardly detectable by most people. This may be due to a polymorphism in the receptor gene that codes for the androstenone receptor.[11] However, the ability to detect the odor varies greatly. It has been shown that the odor can be detected by people down to levels of 0.2 parts per billion to 0.2 parts in 100 million.[12] Several groups report, however, that some individuals who initially cannot smell androstenone can learn to smell it by repeated exposures to it.[13]
In humans, androstenone also has been suggested to be a pheromone; however, there is little scientific data to support this claim.[14][better source needed] The vomeronasal organ is an auxiliary olfactory sense organ responsible for the detection of pheromones as more than just an odor. Most adult humans possess something resembling this organ, but there is no active function. Humans lack the sensory cells that exist in other mammals needed to detect pheromones beyond a smell.[clarification needed][dubious – discuss] Humans also lack the genetic ability to produce these sensory cells actively.[citation needed]
There is also a specific anosmia to the odor in some humans; they are unable to smell specific odors, but have, otherwise, a normal sense of smell. However, this should, by no means, be regarded as indicative for being labeled as a pheromone, as it is true of over 80 olfactory compounds.[15]
To animals, the smell of androstenone can act as a social sign of dominance and can be a way of attracting a mate.[citation needed][dubious – discuss]
Some commercially available products are advertised using claims that they contain human sexual pheromones, including androstenone, and that they can act as an aphrodisiac.[citation needed]
^Pierce, John D.; Cohen, Adam B.; Ulrich, Patricia M. (March 2004). "Responsivity to Two Odorants, Androstenone and Amyl Acetate, and the Affective Impact of Odors on Interpersonal Relationships". Journal of Comparative Psychology. 118 (1): 14–19. doi:10.1037/0735-7036.118.1.14. PMID15008668.
^Dorries, Kathleen M.; Adkins-Regan, Elizabeth; Halpern, Bruce P. (1997). "Sensitivity and Behavioral Responses to the Pheromone Androstenone Are Not Mediated by the Vomeronasal Organ in Domestic Pigs". Brain, Behavior and Evolution. 49 (1): 53–62. doi:10.1159/000112981. PMID8980852.
^Bonneau, M.; Walstra, P.; Claudi-Magnussen, C.; Kempster, A.J.; Tornberg, E.; Fischer, K.; Diestre, A.; Siret, F.; Chevillon, P.; Claus, R.; Dijksterhuis, G.; Punter, P.; Matthews, K.R.; Agerhem, H.; Béague, M.P.; Oliver, M.A.; Gispert, M.; Weiler, U.; von Seth, G.; Leask, H.; Font i Furnols, M.; Homer, D.B.; Cook, G.L. (March 2000). "An international study on the importance of androstenone and skatole for boar taint: IV. Simulation studies on consumer dissatisfaction with entire male pork and the effect of sorting carcasses on the slaughter line, main conclusions and recommendations". Meat Science. 54 (3): 285–295. doi:10.1016/s0309-1740(99)00105-9. PMID22060698.
^Weusten, J. J. A. M. (1989). Biochemical pathways in human testicular steroidogenesis (Thesis). hdl:2066/113615.
^Kirk-Smith, M.D.; Booth, D.A. (1980). "Effect of androstenone on choice of location in others' presence". In van der Starre, H (ed.). Proceedings of the 7th International Symposium on Olfaction and Taste (ISOT VII) and of the 4th Congress of the European Chemoreception Research Organization (ECRO IV): joint meeting held at 'de Leeuwenhorst' Congress Centre, Noordwijkerhout, the Netherlands, 22nd-25th July, 1980. IRL Press. pp. 397–400. ISBN978-0-904147-20-9. OCLC63367504.{{cite book}}: CS1 maint: date and year (link)
