Background: Scientific data on the psychopharmacological effects of new psychoactive substances (NPSs) are scarce. Web fora contain a wealth of information posted by users as trip reports (TRs), but the reliability of the reports remains questionable because of the nature of the used molecule and the potential for dose inaccuracies. We focused on the TRs of designer benzodiazepine (DBZD) users since their psychopharmacological effects are similar to prescription benzodiazepines (BZDs). Moreover, the impact of functional groups on the BZD rings with regards to the potency has been fairly/quite studied, allowing structural analysis. Methods: DBZDs offering more than 15 TRs with at least two accounts on experienced effects were included. Data were analyzed with the empirical phenomenological psychological method. Reported effects were analyzed and the pharmacological potencies of DBZDs were compared by calculating a ‘potency score’. Results: In total, 197 TRs for clonazolam, deschloroetizolam, diclazepam, etizolam, flubromazepam, flubromazolam, meclonazepam, metizolam, nifoxipam and pyrazolam were analyzed. Effects similar to prescription BZDs were reported for all the selected DBZDs. Pyrazolam was reported to be the most anxiolytic DBZD, flubromazolam the most hypnotic, etizolam the most euphoric and flubromazolam and clonazolam as the most amnesic DBZDs. Diclazepam and pyrazolam were not reported to induce euphoria. Flubromazepam, flubromazolam, clonazolam and meclonazepam were the most potent and deschloroetizolam, nifoxipam, metizolam and pyrazolam the least potent. The chemical structure of the different DBZDs and the functional groups on the BZD rings confirmed this ranking, except for nifoxipam. Conclusions: When information on NPSs obtained from Internet fora are abundant, it could be considered as an appreciable data source.