Many signaling molecules and hormones control appetite and satiety in the cellular, peripheral and central nervous systems. In enteroendocrine cells, surges in intracellular calcium concentration trigger release from the basolateral membrane of signaling molecules, including satiation peptides, which diffuse across extracellular fluids to enter the circulation or to interact with nearby afferent nerve terminals from vagal, spinal, and myenteric neurons. As discussed in this review, the gut—brain axis controls appetite and satiety via neuronal and hormonal signals. The Encyclopedia of Nutrition and Good Health 2nd ed. Additional pathways are implicated, however, as oxyntomodulin binds GLP1R times less avidly than GLP1 does, yet they elicit anorexia at equimolar doses
The analysis revealed that some statistically significant weight loss occurred, but the magnitude of the effect is small and the clinical relevance is uncertain. They also found that gastrointestinal adverse events were twice as likely in the hydroxycitric acid group as in the placebo group. When you are considering the potential benefits of products look for meta-analysis studies that take in all the sound research available.
One-off studies that get a significant result are not evidence of anything.