Pherin Pharmaceuticals synthesized a number of pherines and screened them for biologic activity in vitro. PH80 is a pherine shown to bind to a subset of peripheral receptors in nasal chemosensory neurons. Pherines such as PH80 are thought to exert their activity by rapid stimulation of the hypothalamus, which does not require systemic uptake and distribution. PH80 is being investigated as a potential treatment in women that suffer the cycle related symptoms of Premenstrual Dysphoric Disorder.