Flubromazolam: A Designer Benzodiazepine is Studied

Researchers conducted a thematic analysis of internet posts to summarize the desired and adverse effects of the designer benzodiazepine, flubromazolam.

The National Institute on Drug Abuse defines designer drugs as drugs “manufactured to chemically resemble illicit drugs but can often be purchased legally because manufacturers continually modify their chemical structures in order to circumvent drug laws.” Their specific examples include bath salts and spice, a synthetic cannabinoid.1

Of the hundreds of drugs that meet this definition, many are psychoactive compounds, but only a handful classify as a benzodiazepine. Online designer benzodiazepines began with diclazepam, flubromazepam, and pyrazolam, and most recently expanded to include clonazolam, deschloroetizolam, nifoxipam, meclonazepam, and notably, flubromazolam.2 Flubromazepam, pyrazolam, and flubromazolam are structurally similar and classified as narcotic substances in Sweden.

Given the lack of high quality trials and well-documented evidence, researchers from Karlstad University in Sweden conducted a “thematic analysis of anonymous self-reports.” Because patient-reported accounts have proven to be 'surprisingly valuable' in light of scant evidence, the researchers utilized internet drug discussion forums to collect relevant raw data.3

The analysis of patterns in these data revealed five themes3:

  • Onset and duration: Onset varied; though for some users it was as little as 10 minutes, and others reported hours. Duration of effect was reported to be up to several days, providing feelings of relaxation and anxiolytic effects.
  • Desired effects: Users enjoyed several effects of the flubromazolam, which included control of anxiety, manic episodes, and sleep. Some users reported paradoxical effects that encouraged them to be more productive and active throughout the day.
  • Adverse effects and addiction: The spectrum of adverse effects included confusion, inability to walk or talk, addiction potential, sleep paralysis, and sleeping for more than a day with amnestic descriptions of falling asleep. Worsening of anxiety during and after use, depressive symptoms, and loss of libido may counteract the desired effects mentioned previously. Users also described the withdrawal from this benzodiazepine as longer (e.g., longer than a month) and worse than other benzodiazepines (e.g., aches, chills, tremors, cramping, seizures). One user reported temporary blindness.
  • Loss of control: Flubromazolam was described as highly sedating and amnestic. Several users reported additional ingestion of the substance while under the influence, as well as lowered inhibitions that led to police and psychiatric encounters.
  • General estimations and evaluations: Flubromazolam was described as very potent and very sedating, though several users described little to no effects. In general, it was described as unpredictable, with one report of a 2 mg dose being 'zombifying.'

As these are online, individual, self-reported experiences with a non-standardized designer drug, the accuracy of both the reports and the chemical integrity of what was ingested cannot be confirmed.


  • The science behind designer drugs. National Institute on Drug Abuse. https://www.drugabuse.gov/news-events/latest-science/science-behind-designer-drugs. February 9, 2015. Accessed March 14, 2018.
  • Moosmann B. King LA. Auwarter V. Designer benzodiazepines: A new challenge. World Psychiatry. 2015;14(2): 248. doi: 10.1002/wps.20236
  • Andersson M, Kjellgren A. The slippery slope of flubromazolam: Experiences of a novel psychoactive benzodiazepine as discussed on a Swedish online forum. Nordic Studies on Alcohol and Drugs. 2017;(3) 217—229. doi: 10.1177/1455072517706304