Widely used to help with obesity (dieting), PMS, migraines, depression, anxiety, insomnia and addictive behaviour. 5 HTP increases production of serotonin. Serotonin levels in the nervous system are essential for so many aspects of our daily lives. Serotonin is responsible for feelings of well being, satisfaction and for normal sleep patterns. Obesity, PMS, migraines, depression, anxiety, insomnia and addictive behavior have all been associated with low levels of serotonin. Serotonin plays an important role in controlling anger, aggression, body temperature, mood, sleep, human sexuality, appetite, and metabolism, as well as stimulating vomiting.