Foo Fighters frontman Dave Grohl has spoken about the first time he took acid.

Grohl, who was 17 when he first tried the drug, admitted that he was “scared” beforehand, and that his trip lasted longer that he expected.

“I knew that’s a fuckin’ gnarly commitment. It’s like, nine hours,” Grohl told an audience at Hollywood’s Largo Theater.

“I saw this percolator from, like, the Dick Van Dyke show in the 50s and all I could think was, ‘coffee!’

“So I take it down, plug it in, don’t put anything in it, and then, poof! I was thrown to the ground, in altered states, out of my mind!

“I was out for, like, two days. Good blotter, dude.”

Grohl spoke candidly on a range of subjects at the event in Los Angeles, which also featured comedian Greg Proops, according to Rolling Stone.

Foo Fighters live