β-Hydroxythiofentanyl
β-Hydroxythiofentanyl (beta-hydroxythiofentanyl) is an opioid analgesic that is an analog of fentanyl and thiofentanyl.β-Hydroxythiofentanyl was sold briefly on the black market from around 1985,[1] before the introduction of the Federal Analog Act in 1986 which for the first time attempted to control entire families of drugs based on their structural similarity rather than scheduling each drug individually as they appeared.[2] β-hydroxythiofentanyl was anecdotally said to be one of the more favored fentanyl analogs by opiate addicts[citation needed].Side effects of fentanyl analogs include itching, nausea and potentially serious respiratory depression, which can be life-threatening.[3] As of May 2016, β-hydroxythiofentanyl was temporarily listed as a Schedule I controlled substance in the United States.