Singer Katy Perry says she consumes Beta blockers - a drug that treats migraine, high blood pressure and anxiety - every time before going on stage to perform.

The 29-year-old said that she takes pills before getting on stage at her concerts because she doesn't want her nervousness to jeopardise her music career, reports contactmusic.com.

"I have to take Beta blockers, I get so nervous. I think I have to get through this. I can't let these people down, but mostly I can't let myself down," said Perry.

"I've been given a great opportunity and there are 500 bi****s behind me who will snatch my weave off my head if I don't kick-ball-change through this two-hour show. There is a lot of choice out there. All I'm trying to do is make great music," added the singer.

She also said that she would never mix a drug with alcohol, as it can lead to decreased heart activity. However, she doesn't mind a glass of champagne when she finishes a show.

"I always have one drink waiting for me when I get off stage - a glass of champagne," said Perry.