òk-5-MAPB, or BK-5-MAPB, is an entactogen of the benzofuran and cathinone groups which is related to both 5-MAPB and methylone. It was patented by Matthew Baggott and Tactogen and is under investigation by Tactogen for potential medical use.
òk-5-MAPB acts as a monoamine releaser with selectivity for serotonin and has a similar potency to MDMA. In terms of monoamine release, (S)-òk-5-MAPB has shown a / ratio of 0.6 and a / ratio of 2.7, while (R)-òk-5-MAPB has shown a / ratio of 18 and a / ratio of 1.9. In addition, òk-5-MAPB, unlike MDMA, is a potent serotonin 5-HT<sub>1B</sub> receptor agonist.
In rodent drug discrimination tests, (S)-òk-5-MAPB fully substitutes for MDMA whereas (R)-òk-5-MAPB partially substitutes for MDMA and dextroamphetamine at different doses, (R)-òk-5-MAPB and (S)-òk-5-MAPB both generalize to dextroamphetamine, and (S)-òk-5-MAPB but not (R)-òk-5-MAPB substitutes for DOM. Hence, (S)-òk-5-MAPB shows entactogen-, psychedelic-, and stimulant-like effects, whereas (R)-òk-5-MAPB shows more stimulant-like effects, some entactogen-like effects, and no psychedelic-like effects. In other tests, both (S)-òk-5-MAPB and (R)-òk-5-MAPB showed stimulant-like pro-impulsive effects, but (S)-òk-5-MAPB was more potent than (R)-òk-5-MAPB.