If your best friend seems surprisingly unsympathetic to your problems, ask her if she’s taking acetaminophen. The over-the-counter medication may be reducing her empathy as it alleviates her aches, according to a study in the journal Social Cognitive and Affective Neuroscience.
Researchers conducted several experiments with college students who consumed either acetaminophen or a placebo. In one test, the students read scenarios in which someone suffered physical or emotional hurt, such as a knife wound or the death of a loved one. Then the students rated the pain of the story subjects on a 1 to 5 scale, with 5 being the worst possible pain. Those who took acetaminophen rated the pain to be less severe than those who took the placebo.