The Unsettling Side Effect You Didn’t Know Tylenol Had

Photographed by Jessica Nash.
If you're in pain and need to reach for Tylenol, you're probably not in a great mood to begin with. But, new research suggests that the pain reliever could be doing much more than the bottle says — including numbing your emotional responses. In the study published online in Psychological Science, researchers conducted a series of three experiments to see how taking acetaminophen (the active ingredient in pain relievers such as Tylenol) might also affect our emotional processing. In the first two experiments, participants were randomly assigned to take either acetaminophen or a placebo. After an hour of waiting for their doses to kick in, participants were then presented with 40 pictures created to elicit positive or negative emotions. The pictures ranged from extremely negative (malnourished children, for example) to the extremely positive (e.g. kids playing with cute cats). Participants were asked to rate how positive or negative those pictures were, and the level of emotional reaction the participants had upon seeing the pictures. Results showed that participants who'd taken acetaminophen had less extreme responses to the pictures — both positive and negative — than those who'd been given the placebo. They still followed the same pattern of responses, meaning they also rated negative pictures as negative and positive as positive; but, their responses weren't as strong in either direction. And, a third experiment confirmed that the perceived effect was exclusively related to emotional judgements — participants' ratings of color saturation in the pictures were not affected. The study authors concluded, "In all, rather than being labeled as merely a pain reliever, acetaminophen might be better described as an all-purpose emotion reliever." Although this may seem like an extraordinary outcome, the connection between physical and emotional pain has been relatively well-established: There are definitely negative emotional and psychological components that accompany the physical sensation of pain. And, both physical and emotional pain operate on similar neural circuits. So, anything that affects one aspect of pain most likely also affects the other — and, we should take care to address all the different manifestations of pain in the most mindful way possible. But, we wouldn't be so quick to reach for Tylenol as a happy pill.

More from Diet & Nutrition

R29 Original Series