There’s a good chance that what you think you know about the “happiness hormone” is incomplete.
Long associated with the brain and mood, more than 90 percent of serotonin is actually produced in your gut, where it plays a role in regular bowel movements and protecting you from disease. Like a single instrument in an orchestra, serotonin’s sound can be hard to isolate, but learning how it creates a symphony by interacting with numerous systems, other neurotransmitters, and the brain itself could improve your mental and physical health.
