A Redheaded “Knockout?” The mutated MC1R gene has some other surprising effects. Although doctors and medical practitioners have long speculated that redheads were harder to sedate, a recent study from the University of Louisville determined that redheads really do require more anesthesia during surgery. The researchers ran an experiment where they put women under sedation, and then tested their response to pain. The redheaded patients required 20 to 30 percent more anesthetic than other women to achieve the same level of sedation. Scientists at the university also tried to replicate the experiment with mice, and found that animals with a MC1R mutation required more sedation, too. They theorize that the mutated gene somehow has implications beyond hair color, and perhaps affects hormones or enzymes involved in our neurological system.