Kaulitz, 20, told Bild newspaper that someone offered him a Viagra pill during a concert tour of Asia. After first turning down the offer, Kaulitz said he decided to try one. He said a little later he took a second one and fell ill.

"I first asked the seller 'Do I look like someone who needs help with that?'" said Kaulitz, whose brother Bill is the group's lead singer. "He said 'no' — but that I should nevertheless try it out. I popped one in."

Kaulitz, a member of the German rock band that has sold millions of albums around the world, said he took a few more pills used to treat impotence when he got back to his hotel.

"I popped a few more pills, probably too many," he said. "The next morning my head was pounding and everything in front of my eyes was blurry. It wasn't fun anymore. It was pretty bad."

Kaulitz said it took two days for the effects to wear off.

"Unfortunately there were situations where it just wasn't appropriate," Kaulitz said.