Medicine & Health
What is Serotonin?
Serotonin is a chemical messenger (neurotransmitter) that helps regulate mood, sleep, appetite, and digestion. Often called a 'feel-good' chemical, it helps stabilize mood and is a major target of many antidepressant medications.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains serotonin.
Key things to understand
- 1It carries signals between nerve cells in the brain and also acts widely in the gut.
- 2It influences mood, sleep, appetite, memory, and even blood clotting.
- 3Most of the body's serotonin is actually made in the digestive tract, not the brain.
- 4Many antidepressants (SSRIs) work by keeping more serotonin available between neurons.
- 5It is a precursor to melatonin, the hormone that helps control your sleep cycle.
Frequently asked questions
- Does serotonin make you happy?
- It helps stabilize and lift mood, but happiness involves many chemicals and circumstances — serotonin is one important piece, not a simple 'happiness switch'.
- How do SSRIs use serotonin?
- SSRIs (selective serotonin reuptake inhibitors) slow how fast neurons reabsorb serotonin, leaving more available to ease symptoms of depression and anxiety.
- How is serotonin linked to the gut?
- Around 90% of the body's serotonin is produced in the gut, where it helps control digestion — part of the close 'gut-brain' connection.