HMB is a natural substance produced in your body by the conversion of the amino acid lucene. But your body only produces a small amount of it, enough to signal to the body to keep the muscles it has from breaking down under normal circumstances. However, when you are doing strength training, you are putting unusual and unexpected strain on your muscles that can cause them to become overly damaged. Supplementing with HMB under these conditions will help the body keep the muscle it has healthy while supporting the creation of more muscle. Some people in the past have supplemented with extreme amounts of the amino acid lucene to get this effect but taking HMB directly is safer and more effective.
Read up on the science. Learn how it works. You shouldn't take any substance without fully understanding the advantages and disadvantages.
Now that you have learned all about how HMB is a safe, natural, effective way to shorten recovery time, start using it.