Grey's Anatomy star Ellen Pompeo has credited the TV show's gruelling shoot schedule with helping her mimic an authentic medical intern.

Pompeo, who plays Meredith Grey in the hit series, says the long hours of filming on set help her look tired - something she believes is necessary to convincingly portray a young doctor.

However, she's worried balancing hectic hours in a bid to create a more authentic visual role has its downside too.

Pompeo says, "Well, the good thing about the show, I will say, is that we're supposed to look, and be, tired because we're interns.

"(But) sometimes I look in the mirror and think, 'Oh, God.' Your eyes are the first things that go when you're that tired. So, as a girl, I feel a little like I maybe don't look so great all the time."