Testosterone is the part of HGH...hormones are responsile for muscle gain..so.. Testosterone boosters will increase your testosterone levels to help you gain muscle.Testosterone is a hormone that is responsible for the growth of male sex characteristics. Although, it is mainly present in men, testosterone can also be found in small quantities in women.Testosterone is necessary for bone and muscle production, and also to increase libido. Many times, the testosterone level in the body goes down because there is less production of the hormone in the body. In such cases, doctors prescribe testosterone boosters to the concerned person.

The side-effects also depends on the type of testosterone boosters that a person takes. They are available in two types, viz. one which is legally prescribed and used and the other is that which is illegal. While testosterone boosters, like creatine, are safe for the health of a person, one must totally avoid the use of anabolic steroids, which may give immediate results, but may have many side effects.