Natural redheads need 20% more anesthesia than other people report scientists. “Redheads are likely to experience more pain from a given stimulus and therefore require more anesthesia to alleviate that pain.” said Dr. Edwin Liem of the University of Louisville in Kentucky. Anesthesiology is still very much a mystery to scientists, and picking the right dosage that keeps someone out without killing them is still very much an art. Studies like this will help them determine how anesthesics work and why.