Tokio Hotel rocker Tom Kaulitz has sworn off using sex aid Viagra ever again after a bad experience with the drug left him struggling to see straight.

The German guitarist, 20, reveals he was approached by a dealer while on tour with the band in Asia and initially felt offended by the offer - before relenting and deciding to buy a handful of the pills.

Kaulitz tells Germany's Bild newspaper, "I first asked the seller 'Do I look like someone who needs help with that?' He said 'no' - but that I should nevertheless try it out. I popped one in."

The star decided to take a few more once he returned to his hotel - but he soon regretted his actions when he woke up.

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

And Kaulitz admits the sex drug's performance-enhancing effects left him red-faced for two whole days.

He adds, "Unfortunately there were situations where it just wasn't appropriate."

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