COLUMBUS, OH (CBS) —  Acetaminophen is one of the most popular pain relievers in America, but a new study has discovered a new side effect.

Ohio State University researchers found acetaminophen not only dulls your pain, but it also reduces your positive emotional response.

Researchers had participants in the study view pleasant and disturbing photos after taking the drug.

Those who had taken acetaminophen did not react as strongly to the photos as those who were given a placebo.

According to the study, 23 percent of all Americans use one of the more than 600 medicines that contain acetaminophen each week.