Zac Efron refuses to `confirm or deny` if he has ever tried Viagra

London: Zac Efron recently refused to answer talk show host Conan O`Brien`s question about whether he has tried viagra in his life clearly.

` The Awkward Moment` star said that he couldn`t confirm or deny it if has ever taken the drug, but claimed that someone he knew did take just a tiny bit of it, the Mirror reported.

When O`Brien asked the former Disney star if the so-called friend was actually him, Efron continued saying that the drug had turned the guy into a horse.