Chemicals in the brain that reduce feelings of pain and increase feelings of well-being. Endorphins are produced by the pituitary gland and by a part of the brain called the hypothalamus in response to stimuli such as strenuous exercise, pain, and orgasm. Endorphins are similar to the pain-relieving drugs known as opioids, which include morphine. In fact, the word “endorphin” means “morphine-like substance inside the body.” Like opioids, endorphins latch onto receptors in the brain to temporarily block pain signals.
Endorphins are thought to be responsible for “runner’s high,” the euphoria people experience after periods of moderate-to-intense exercise. In 2008, German scientists published a study in the journal Cerebral Cortex that examined runner’s high. They used positron emission tomography (PET) scans to compare endorphin levels in 10 male runners’ brains before and after a long run. They found that endorphins were being produced during running and attaching themselves to receptors in parts of the brain associated with emotion and mood.
Because endorphins are natural pain relievers, they may be able to help people manage the symptoms of arthritis. For example, some people with arthritis find that their joint pain and feelings of anxiety or stress diminish after exercise. In addition, it has been speculated that the reason some people find pain relief from acupuncture, a complementary therapy involving the insertion of needles into the skin, is that the needles stimulate the release of endorphins in the brain.