Male fertility can be defined as the ability of the male reproductive system to impregnate a woman, while infertility is the condition of a married couple who have been married for one year or more and have had sexual intercourse regularly or without using contraception but do not have a pregnancy or offspring. About 10% of married couples experience infertility. The main organ of male reproduction is the testes because in the testes the process of forming spermatozoa and the hormone testosterone occurs. The hormone testosterone plays a direct role in the continuity of spermatogenesis. Testosterone is produced through a series of steroidogenesis mechanisms in testicular Leydig cells. Several factors influence the course of steroidogenesis such as Leydig cells, steroidogenesis proteins, related genes to the influence of free radicals. These factors are closely related to diet and lifestyle. This study is important to understand in efforts to prevent infertility in men.