Smiling might make a vaccination shot hurt less, researchers say

Study finds a grimace also lessens pain of getting stuck with a needle

5 Surprising Health Benefits of Smiling

For those afraid to get the COVID-19 vaccine because they think the shot will hurt, researchers at the University of California, Irvine, have a suggestion: smile.

A “sincere smile … can reduce the pain of a needle injection by as much as 40 percent,” the researchers wrote. If you can’t find your smile while getting punctured with a needle, they say, a grimace works just as well.

“When facing distress or pleasure, humans make remarkably similar facial expressions that involve activation of the eye muscles, lifting of the cheeks and baring of the teeth,” principal investigator Sarah Pressman, UCI professor of psychological science, said in a university news release. “We found that these movements, as opposed to a neutral expression, are beneficial in reducing discomfort and stress.”

For their study, the researchers asked 231 people to self-report their level of pain, emotion and distress while getting a shot of saline solution using a 25-gauge needle, the same size used for flu shots.

Participants were randomized to express either a Duchenne smile —one that elevates the corners of the mouth and creates crow’s feet around the eyes — or non-Duchenne smile, a grimace or a neutral expression.

Those in the Duchenne smile and grimace groups reported the injection hurt only about half as much as those in the neutral group said, indicating smiling or grimacing can make a positive difference in the needle stab experience.

A more sincere Duchenne smile was also associated with significantly lower heart rates, the researchers found.

The study was published online in the journal Emotion.