Hydroxycitric acid is directly responsible for an increase in the serotonin (a hormone) levels in the human body. The utilization of these drugs poses potential dangers to your well-being. With so many people fighting obesity, it's no surprise that pharmaceutical companies are trying to cash in by exipure products to help the public fight excess fat. Substances such as capsaicin that are found in peppers as well as caffeine and niacin (vitamin B3) are effective to speed up body metabolism.