Aye - right at the start, right after Hughie's recruited (third or fourth issue?), Butcher injects him with blue which IIRC he gets pure from his squeeze in the CIA. Poor quality cut blue was IIRC how the numerous sex workers were able to be used and abused by superheroes without being reduced entirely to mush, although the effects of that only lasted a few days.
Having not seen the series (there's so much stuff that never gets finished these days I tend not to bother until the run is done), how do they get around the "normal humans going toe-to-toe with superheroes" problem then if they Butcher and co aren't dosed up on supe-juice?