In older men doing strength training, taking HMB-free acid supplements for six weeks did not lead to measurable improvements in strength, muscle size, or maximum force production compared to a placebo, even if there was a slight increase in lean mass.

We analyzed two assertions about HMB-free acid and older men doing resistance training, and both point to the same conclusion: there is no measurable benefit in muscle strength, size, or maximum force production compared to a placebo after six weeks of use. One assertion noted a slight increase in lean mass, but this did not translate into stronger muscles or greater power output [1]. The other assertion directly stated that HMB-free acid did not lead to greater gains in strength, muscle thickness, or force production than a placebo [2]. Together, these findings suggest that, at least over a six-week period, HMB-free acid does not appear to enhance the physical results of resistance training in older men beyond what can be achieved with training alone. We did not find any evidence showing harm or negative effects, but we also did not find any clear advantage. The evidence we’ve reviewed so far leans toward no meaningful benefit for strength or muscle growth, even if there may be a small change in lean mass. This does not mean HMB-free acid has no role in health — only that, based on what we’ve seen, it doesn’t seem to help older men get stronger or bigger muscles faster from resistance training. If you’re an older man lifting weights, focus on consistent training and adequate protein — those are the factors with stronger support.