I've tried bk-MBDB recently and was quite impressed with most sides of it.
150 mg was eaten after due testing for idiosyncratic reactions the week before.
Then at around T+6:00 I was so into it I supplemented around 80 mg which I thought I read somewhere would not be that active at that time.
Well, after the 2nd dose I was totally up again and the dropoff now suddenly took forever. The next day, the whole day I still had the body buzz, which is very pleasurable IME.
I had done my homework and from anecdotal 'evidence' I distilled there might be opening up to some serious solarplexus originating energy flows. This is probably true for most empathogens, you suddenly feel sincerely with your heart. Another thing I predicted was also noticed: it is pretty easy to loose control over your emotions which are flaky, enhanced, accessed directly with crystal clear reception. But the 'push' of this stuff is stronger than it is directed so when left unguided they can steer a bit in worse directions. Luckily this mechanism was readily adopted.
Like I said after the second dose the potential just didn't clear up! With certain types of meditation I could call upon the same well of force which is all probably associated with serotonin systems.
Personally I prefer methylone to MDMA because it is more gentle in a way. When you find blissful happiness on such a substance I like it better when I work my own way up there. Besides I believe it's no coincedence that MDMA delivers a pretty heavy hangover (at least for me) and the bk's seem to have this much less. I'm wondering what mechanism is behind this, is it the flooding release of 5-HT that relentlessly exhausts your brain on MDMA. While reuptake inhibition which I believe to be relatively stronger in the bk's and maybe some other analogue empathogens is maybe something more malleable and doesn't result in such harsh neurotransmitter exhaustion.
I was preparing for at least some emotional setback but this monday I had a seriously bitchin good day! This makes me say it's worthwhile for me, having beneficial effects, feeling heavenly but not neccessarily too good to be true (or healthy) while negative effects for me did not exceed tiredness, fatigue. But no wonder I felt this, this substance didnt allow me to eat much for about 2 days! Now this much appetite repression I wasnt expecting from something hardly that speedy (relaxing even) although if I compare with other stimulants
it may be acceptable. Oh yeah there was also vasoconstriction, paraesthesia in the extremities going as far as a crampy powerless feeling. I wouldn't say the body load is that heavy but I bet your BP and HR soar if you take a sufficient amount.
Mephedrone (4-MMC) which I also tried and am on now(!) doesn't exhibit that much appetite depression or typical stimulation. I know thats not what this topic is about but damn that stuff feels good looking at the presently known costs (costs in a broad sense, research chemicals equal unpredictability to some extent.
Anyways - good shit, watch your reaction and adjust your dose carefully and responsibly. I wouldnt care to party on bk-MBDB, it's just too sensitive a state at the plateau.