Although serotonin is well known as a brain neurotransmitter, it is estimated that 90 percent of the body's serotonin is made in the digestive tract. In fact, altered levels of this peripheral ...

Serotonin sends signals between nerve cells. It may help regulate many body functions, including mood, bowel movements, and sleep. Some medications help boost serotonin levels and improve mood.

Serotonin syndrome occurs when a person takes drugs that cause excess levels of serotonin to accumulate in the body. Symptoms can include agitation, a dry mouth, dilated pupils, confusion, and more.

Serotonin is nature's own appetite suppressant. This powerful brain chemical curbs cravings and shuts off appetite. It makes you feel satisfied even if your stomach is not full. The result is eating ...

Serotonin is sometimes known as the happy chemical, because it appears to play an important role in regulating mood, and low levels of serotonin in the brain have been associated with depression. (1) ...