Anecdotally, dentists and anesthesiologists have for decades reported that redheads usually require more anesthesia than those with other hair colors (about 20%).  Recent research has confirmed that redheads are actually more sensitive to certain types of pain due to a genetic mutation that also makes them redheads. (For all the blondes out there – this only applies to natural redheads – changing your hair color won’t affect your pain tolerance. 🙂

Read more here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692342/