An androgen is any type of substance, natural or synthetic that creates sex characteristics in males. These substances are known as steroid hormones. The most well-known example of a steroid hormone is testosterone, which is produced by the testes in the male reproductive system. Parts of the reproductive system also are classified as parts of the endocrine system as well, which is a group of organs that influence other parts of the body by use of hormones, which act as chemical messengers.
Testosterone is a steroid hormone that influences both primary and secondary sexual characteristics in males. It causes males to have more muscle mass than females typically have. It is also responsible for the deepening of the voice and the increase of body hair. Testosterone is also influential in energy levels and libido, which is the male sex drive. So any of the cells in the male reproductive system, primarily those of the testes would be cells that are responsible for the production of androgens.