True or false endorphins are body-produced chemicals that relieve pain in case of injury.

The answer is true. Enhanced self-esteem is a key psychological advantage of regular physical movement. When you exercise your body discharges chemicals named endorphins. These endorphins act together with the receptors in the brain that lessen the sensitivity of pain.  Endorphins also initiate a positive feeling in the body alike to that of morphine. Endorphins deeds as analgesics which means they reduce the perception of pain. They also deed as sedative in which they are vital in the brain, spinal cord and many other portions of the body and are on the loose in response to brain chemicals named neurotransmitters. 

The answer is one amu.