Serotonin is mainly produced by cells in the brainstem and hypothalamus (also in the lungs, spleen, and cells of the intestinal mucosa) is formed from L-tryptophan. It has numerous central and peripheral effects. It regulates body temperature, sleep and also aspects of our emotional world. (Missing) serotonin is also associated with depression.
Serotonin belongs together with dopamine, noradrenaline and adrenaline to the group of [[catecholamines]. It functions in the organism on the one hand as tissue hormone and on the other hand as neurotransmitter in the intestinal nervous system (95%), central nervous system, cardiovascular system and in blood.
Serotonin is a neurotransmitter with a dampening effect. It is strong mood-lightening, relaxing, sleep-promoting, antidepressant, pain-inhibiting and motivational.
Serotonin also has a positive effect on the feeling of satiety and thus regulates appetite. It also has an analgesic effect. Serotonin deficiency, exacerbated by melatonin and dopamine deficiency (melatonin is a hormone produced from serotonin in the pineal gland (epiphysis) and controls the day-night rhythm of the human body) can lead to depression, anxiety, lack of concentration, insomnia, migraine, non-specific connective tissue pain, sensory disorders and severe fatigue (chronic fatigue syndrome, CFS).
https://de.wikipedia.org/wiki/Serotonin (Wikipedia CC-by-sa-3.0)