now that could actually be a possibility, as I'm sure they all use different fillers. But i dont know about the difference between UG and HG though, I've had some of my best gains on UG. In fact, one of the UGs that I use just came out with a new dbol part way into my cycle, so I jumped on it, and in weeks 4 and 5 of my cycle, I gained a total of 9lbs, which really impressed me