Coffee is far better treatment for chronic pain than over-the-counter pills, new research shows.
Feeling tired drastically increases pain sensitivity, the study found.
To counteract that, scientists from Boston Children's Hospital gave exhausted lab mice either painkillers, coffee or more time asleep.
They found the most wide-awake mice - after a jolt of caffeine or a long sleep - were more impervious to pain than those on painkillers.
In the caffeine-drinking mice, they saw a rush of dopamine to the brain's pleasure center, which alleviated their feelings of pain.