Updated: 2/18/2020

If you have red hair, you might want to go ahead and ask for extra anesthetic at the dentist’s office. Studies show that not only are redheads more likely to experience sensitivity even after receiving painkiller, they also tend to have more dental anxiety as a result.

Genetics Study on Redheads

Researchers found that people with natural red hair tend to be more resistant to local anesthetic. They said that many redheads avoid the dentist as a byproduct of the additional anxiety due to perceived pain. The study, entitled “Genetic Variations Associated With Red Hair Color and Fear of Dental Pain, Anxiety Regarding Dental Care and Avoidance of Dental Care ” was published in The Journal of the American Dental Association. Researchers studied 77 dark-haired participants and 66 who had naturally red hair, all in the 18-41 age range. They measured anxiety levels (general and dental-specific), dentist avoidance, and also analyzed genetic differences in blood samples.

Dental Pain Results

Out of the 144 participants, 85  had a particular gene variant commonly associated with redheads. Participants with red hair comprised 65 of the 85. Those with the gene variant were twice as likely as those without it to steer clear of the dentist. Results showed that they also had significantly more fear of dental pain than the others.

Dental Anesthetic

An article in The New York Times entitled “The Pain of Being a Redhead”, said they typically need about 20% more anesthetic than those without the gene variant because the same gene that causes red hair also appears to affect the body’s sensitivity to pain. According to one of the researchers, the study was actually started to see if there was any validity to the urban legend among the community that red-haired patients were harder to anesthetize.

In light of these results, researchers advise dentists to evaluate red-haired patients ahead of time and be prepared to administer more anesthetic if necessary as well as help patients cope with anxiety.