Just thought this info might be useful. I've seen posts on this board with people saying they wouldn't touch brown powder heroin because they thought it was impure.
Previously all the white heroin I'd ever run across was mostly quanine cut with a little dope in it, really weak.
Well the other day I finally got some white heroin.. disolved immediately an in entirety, unlike the brown stuff which was stronger but left small pieces in the water. This disappeared and virtually did nothing to the water color as well. I'm pretty sure it was just heroin.. decent, not the strongest, but decent.
I'd be skeptical about actually finding fentanyl sold as china white, though.