endorphins

Look to other sources for a scientific point of view. What follows below is a purely subjective perspective.

Endorphins

Google Endorphins and you'll get a raft of info, so here's the short version: When you take heroin, or do more than a 25 minutes of physical activity, you release a substance into your body that creates a feeling of well being. That can be a good thing, in the latter case. Read more »