Why are scientists all over the world studying Garcinia Cambogia and the effects of HCA (Hydro Citric Acid)? What is science so curious about? Research is focused on HCA extract from Garcinia Cambogia as a weight loss aid in two powerful ways. Blocking Fat. HCA’s chemical composition can inhibit a key enzyme that your body needs to make fat from carbohydrates: Citrate Lyase. Typically, carbohydrates (sugars) that aren’t used immediately are either stored or converted to fat. HCA has been found to inhibit citrate lyase, which halts the fat-making process and decreases the production of bad cholesterol. Suppresses Appetite Researchers are also encouraged by HCA’s ability to increase serotonin levels. key to suppressing appetite. Serotonin is a neurotransmitter in your brain that makes you feel good. By increasing serotonin levels, HCA improves mood and suppresses emotional eating during stressful times.