Taking Acetaminophen Might Reduce Your Empathy, Study Says

Could taking acetaminophen reduce your sensitivity to other people's pain?
Acetaminophen, the main ingredient in Tylenol, can cause liver damage when taken in excess. Gary Cameron/Reuters

Acetaminophen, the main ingredient in Tylenol, is meant to reduce the user’s physical pain. According to a study published Tuesday, it also reduces one’s ability to feel other people’s pain.

When researchers from Ohio State University gave college students the popular over-the-counter drug, they were less able to empathize with physical or social aches of other people, according to the paper, published in the journal Social Cognitive and Affective Neuroscience.

"These findings suggest other people's pain doesn't seem as big of a deal to you when you've taken acetaminophen," Dominik Mischkowski, a co-author of the study and researcher at the National Institutes of Health, said in a statement

The researchers measured the empathy of 80 college students by having them read several stories about other people's’ suffering: One narrative involved a person enduring a knife cut that went down to the bone, and another described a person suffering the death of his father. The students who took the acetaminophen rated the pain of the characters in the story lower than those who took the placebo.

In a second experiment, the researchers tested 114 college students’ response to unpleasant noise, by exposing them to two-second blasts of high-decibel sound. Those who had taken the acetaminophen rated their experience of the sound to be less unpleasant than the students who took the placebo, and they predicted the sound blasts would be not so bad for other people, either.

Acetaminophen is the most common drug ingredient in the United States, and is an ingredient in more than 600 drugs on the market. Nationally, about 23 percent of the adult population takes acetaminophen every week.

Baldwin Way, an assistant professor of psychology at the University of Ohio and another co-author of the study, cautioned that taking the drug could have implications for our interpersonal lives.

"Empathy is important. If you are having an argument with your spouse and you just took acetaminophen, this research suggests you might be less understanding of what you did to hurt your spouse's feelings," Way said in a statement. 

Previous studies have shown that the same region of the brain is activated when a person experiences pain as when one imagines another person experiencing pain, which could help explain these results, according to the researchers. They plan to look next at whether the same holds true for ibuprofen, another popular painkiller that is the main ingredient in drugs like Motrin.