HMB

 

Beta-hydroxy beta-methylbutyrate (HMB) is a molecule that’s produced when your body processes the amino acid leucine.

HMB is responsible for some of the beneficial effects of protein and leucine in the diet (39Trusted Source).

It may be especially important for reducing the breakdown of muscle proteins (40).

While HMB is produced naturally by your body, taking it as a supplement allows for higher levels and may benefit your muscles (40, 41Trusted Source).

Several studies in previously untrained adults have shown taking 3–6 grams of HMB per day can improve the gains in lean body mass from weight training (42Trusted Source, 43Trusted Source, 44Trusted Source).

However, other research shows that similar doses of HMB are probably not effective at increasing muscle mass in adults with weight training experience (45Trusted Source, 46Trusted Source, 47Trusted Source).

This may mean that HMB is most effective for those who are getting started with exercise or increasing the intensity of their workouts.

Shop for HMB supplements online.

Summary: HMB may help increase muscle mass in those who are
beginning a weight training program, but it appears to be less effective for
those with training experience.