HMB, or beta-hydroxy-beta-methylbutyrate, is a compound that the body produces from the amino acid leucine. It is often used as a dietary supplement to support muscle health, particularly in individuals engaged in intense exercise or those recovering from illness. HMB is believed to help reduce muscle breakdown and promote muscle growth. Research suggests that HMB may enhance strength and improve recovery times after workouts. It is commonly taken by athletes, bodybuilders, and older adults to maintain muscle mass. However, while some studies show positive effects, results can vary, and more research is needed to fully understand its benefits.