6-alpha-Naloxol is active metabolite of naloxone. 6-alpha-Naloxol was shown to be neutral antagonist at the mu receptor in vitro, with no affect on cAMP levels or GTPitalic gammaS binding, regardless of morphine pretreatment. It elicits withdrawal behaviour and conditioned place aversion in morphine pretreated rodents.

5-(2-Aminopropyl)benzofuran (5-APB) is an empathogenic psychoactive compound of the substituted benzofuran, substituted amphetamine and substituted phenethylamine classes. 5-(2-Aminopropyl)benzofuran is a serotonin–norepinephrine–dopamine reuptake inhibitor and serotonin–norepinephrine–dopamine releasing agent. The toxicity and long-term health effects of recreational 5-APB use do not seem to have been studied in any scientific context and the exact toxic dosage is unknown/ 5-(2-Aminopropyl)benzofuran 's high affinity for the 5-HT2b receptor makes it likely that 5-APB would be cardiotoxic with long-term use, as seen in other 5-HT2B agonists such as fenfluramine and MDMA.