Beta-hydroxy-beta-methylbuteric acid, or HMB, is a metabolite of the essential amino acid Leucine. HMB is thought to play a role in the regulation of protein breakdown in the body. The theory began that taking supplemental HMB could possibly slow the breakdown of protein in the body, thus increasing muscle mass, strength, and ultimately decreasing body fat. In the 1990's, scientists began to test this theory, first in animals, and then in humans.
Below is a series of links so that you may read most of the research done on HMB for yourself. In all of the studies presented, you will see that indeed, HMB is supported scientifically to be a strong ergogenic aid in increasing muscle mass, strength, and decreasing body fat in all age groups. Before you run out to the supplement store (like I almost did), lets take a look at some of the underlying facts about the HMB research that may change how you feel.
Never before have I seen a nutritional supplement with so much apparent support of its efficacy. The research indeed reads like a dream come true. But could this all really be possible? Much of the research you will see on HMB will have one or both of the following names listed as researchers involved in the study: Steve Nissen and Scott Connelly. Steve Nissen is the chairman of MTI, who holds the patent on HMB. Scott Connelly is the owner of MET-Rx, which sells products that contain HMB.
How valid is any research done by people financially invested in the sale of the product being tested? Most would say, not very. In addition to this, there are numerous methodological flaws in much of the early research done on HMB, adding to the suspicion that the studies were "fixed" to sway the results.
The positive side is that more recent research involving different researchers and better methodology is still showing that HMB is indeed effective as it claims to be. What role financial gain has in that research is still questionable, but at least it seems that "foul play" is less likely in the research done within the past few years.
Considering all of this information, what can be said about the validity of HMB? At this point, no definitive conclusion can be drawn. There is indeed a lot of evidence to support the use of HMB in active people, albeit at least some of it flawed. Like most supplements, safety of using it is for the most part, unstudied.
Still, however, when compared to other nutritional supplements on the market, it seems there is more validity to taking HMB than other products such as L-carnitine, chromium picolinate, vanadyl sulfate and MCT's. It is indeed possible that HMB IS the wonder supplement that it claims to be, if you can trust the research.