While that seems like a pretty significant difference, the findings are more nuanced than that. For starters, in this study, muscle mass was the only variable that changed between the groups. Muscular strength, for example, stayed the same between the two groups after the 10 weeks. So, even though their muscles grew, their strength didn’t necessarily improve. Given these confusing findings, there need to be more studies performed before experts can conclusively say, the pill limits muscle gains.