Natural redheads require about 20% more anesthesia to stay unconscious during surgery.

This phenomenon is linked to the Melanocortin-1 receptor (MC1R) gene mutation, which is responsible for red hair and fair skin. Research led by Dr. Edwin Liem and published in the journal 'Anesthesiology' in 2004 confirmed that redheaded women required significantly more desflurane gas to remain sedated. The study found that these individuals needed approximately 19% more anesthesia compared to those with dark hair.The MC1R gene belongs to a family of receptors that include pain receptors in the brain. Because the mutation affects these receptors, it alters the body's sensitivity to pain and its chemical response to sedative drugs. This genetic quirk makes redheads more susceptible to thermal pain but surprisingly more sensitive to opioid painkillers like morphine.Further studies at the University of Louisville showed that redheads are also more resistant to local anesthetics such as lidocaine. This means they may require larger or more frequent doses for dental work or minor procedures. Understanding these genetic differences is crucial for anesthesiologists to prevent patients from waking up or feeling pain during operations.