I am finding a combination of MDAI and bk-MDMA to be particularly lovely as a euphoric entactogen. In my experience, if one lines up all the abovementioned in a line from stimulant-like to entactogen-like, it goes something like MDPV, bk-MBDB, 4-MMC, bk-MDMA, MDMA, MDAI. I guess that maybe reflects a dichotomy between mostly dopaminergic and mostly serotonergic action; but I'm not sure what the objective data on that are (or whether my personal experience accords with most other people's experiences). Anyway, personally, I feel that bk-MDMA lacks some of MDMA's entactogenesis, while MDAI lacks some of its more stimulant euphoric aspects, hence the rather loveliness of the combination. I haven't yet worked out the ideal ratio and dosage for me yet, but perhaps somewhere in the region of 150 mg of each. (But you should start much lower, of course, and not in combination, to be on the safe side!

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Re: bk-MBDB, I have always found it to be more stimulant, with the emphasis on unpleasant stimulant side-effects like gurning etc.