Zach Galifianakis Does 'Heroin' On Bill Maher's 'Real Time'

They do say that marijuana is a gateway drug. And having darkened that doorway ad nauseum, Zach Galifianakis took the next step: heroin. On live television.

Galifianakis appeared Friday on "Real Time with Bill Maher," ready to yuck up some awkward laughter, give his political insights and, hey, promote his new film, "The Hangover: Part II." And while the flick involves some serious partying -- it's in the name! -- Maher had Galifiankis take it to the extreme, far beyond anything his character Alan has done in the outrageous R-rated flicks.

To up the ante from Galifianakis' infamous October appearance on the show, during which he lit up a (fake) joint to advocate for the legalization of marijuana, Maher took out a tray of heroin paraphernalia for the star, who was instantly game to loan his veins. Of course, the smack was fake, and there wasn't much needle action going on anyway, but it was another memorable moment for the irreverent pair.

Which only begs the question: how do they take it to the next level in his Galifianakis' next appearance? And was Zach's mother watching this appearance?