We have already covered some of the functions of hydroxy-citric acid, the active substance in garcinia cambogia, on glucose and fat metabolism. Those, however, are not its main functions. The activity that HCA primarily performs in the body is stimulation of the production of new serotonin. Serotonin is a hormone and neurotransmitter (i.e., remember, a substance that conveys information between the cells of the nervous system) also known as the ‘happiness hormone’ because it is responsible for the establishment of a sense of contentment. It is precisely for this reason that many drugs for the treatment of depression have the function of increasing the amount of serotonin. Now, the fulfilment that results from the secretion of this substance also implies a sense of hunger. In other words, an abundance of serotonin in the body has an anorectic effect. The obvious consequence is that garcinia cambogia supplements can reduce the sense of hunger in the context of low-calorie diets. Another ancillary, but not negligible, function of HCA is the enhancement of the lipid oxidation process. As far as side effects, form and dosage are concerned, the reader is referred to the section on garcinia cambogia in the section on products for blocking new fat.