The Lord of the Rings: The Two Towers star is currently travelling across America in support of her new futuristic family film, and Tyler admits she has been struggling to get on with her promotional duties as she has been high on antibiotics.
Apologising to fans while taking a seat on Late Night with Jimmy Fallon, she said, "I have a little sinus infection so if I sound strange, excuse me... I feel like I have cotton balls in my head."
And the actress admits the medication, called Azithromycin, is giving her crazy side effects.
She adds, "I'm on a 'Z-Pak', which is like the crazy steroids. It makes you feel like (superhero) The Incredible Hulk. You feel like you have a tremendous amount of power, that's completely false."