It took 36 pairs of underwear and 450 gallons of blood to film the sex scene between Amy Dunne and Desi Collins, where she slits his throat in the 2014 film Gone Girl.
Director David Fincher told Vanity Fair magazine: "I told them to rehearse it for three days, as we're pumping five gallons of blood out of Desi's throat."
She believes that she spent more time on camera on Gone Girl than in any other film.
She said: "I spent more time in front of the camera on that film than in my entire career to date, because he's [Fincher] shooting five to six hours of footage a day, and over a hundred days shooting -that mounts up."
Even though Pike was involved in a lot of movies last year, she is still very private about her personal life and talks very little about her partner Robie. She is very grateful that he is not fame hungry.
She added: "The quality I most admire about him is he sees the value in anonymity."
The full interview with Rosamund can be read in the February issue of Vanity Fair magazine.