Flunitrazepam is a long-acting hypnotic benzo. 1 mg is the normal therapeutic dose, and should be equivalent in intensity to .5 mg of xanax, albeit far longer lasting and more sedating.
Being a highly lipophilic compound, it is hard to give an exact duration of action. I believe the half-life is around 24 hours for flunitrazepam, though these compounds tend to have a "biphasic" half-life where the concentration ramps up quickly as it is rapidly absorbed (you should feel it within 20-30 minutes after ingestion), then decreases at first quickly (as it is being distributed across the fatty tissues in your body) then gradually (as the compound is being metabolized).
So the effective „duration of action“ is probably around 6 hours.
A lot of people claim that benzos are considered non-recreational or useful mostly as potentiators for opioids or comedown aids for stims; however people with anxiety in particular are going to find benzos perfectly recreational on their own. Needless to say, these people are the most at risk for benzodiazepine addiction, which can be extremely destructive to your social life and personality.
