GHRP-6 antagonising the peptide Ghrelin, it mimicks it, but actualy fights against it causing the signal for gastric emptying and hunger. Ghrelin is what many believes causes obesity, and insulin resistance amongst other things, and i believe this is one way by wich GHRP-6 may help reduce fat, by fighting against it in effect ... but, and there is always a but, if you take more than 150mcg the effects of the gastric emptying can be so strong that you may have the urge to severely stuff yourself with foods, so if your on a bulk this is a great side effect, and considering the price its a very good one, so on a bulk i rate this as the number one aid in increasing appetite, as you get very good anabolic effect too and increased strength