The 5-hydroxy-tryptophan is an amino acid, which is turned into serotonin (i.e. the “happiness hormone”) inside the brain. The decreased levels of serotonin in the brain can lead to a variety of problems like: depression, headache, increased craving for sweets and others. 5-hydroxy-tryptophan reduces the appetite for sugar and simple carbohydrates and which gradually results in a lowered body weight. It also helps to drop bad habits like smoking or drinking alcohol.