Actress Lizzy Caplan downed vodka first thing in the morning to overcome her nerves before shooting sex scenes on racy vampire Tv series True Blood.

The Mean Girls star was cast as Ryan Kwanten's love interest in the first series of the hit show, and had to strip off for a series of raunchy shoots during her first few days on set.

Caplan was so terrified, she knocked back booze while completely naked as the make-up artist worked on her.

Speaking to U.S. Tv host Chelsea Handler, she recalls, "I was hammered for that. I didn't really have lines the first time. It was like seven in the morning and I was chugging vodka completely naked while a make-up artist I had just met was on her knees in front of me sponging my a**. It's intimate."

The star admits she drank too much and embarrassed herself in front of the crew, adding, "I was so nervous and I was so drunk that after I shot the scene I was going up to the crew members, and I had just met all these people the day before, and I was going up to all of them like, 'You got a boner (erection)! You do! You've got one!' It was horrible. Horrible!"