Androgen is a type of steroid hormone that is primarily responsible for the development and maintenance of male characteristics in the body. The most well-known androgen is testosterone, which is produced primarily in the testes but also in smaller amounts in the ovaries and adrenal glands. Androgens play a critical role in the development of male sex organs, deepening of the voice, growth of facial and body hair, and muscle and bone development. They also play a role in the regulation of libido and mood. In females, androgens are produced in smaller amounts in the ovaries and adrenal glands, and play a role in the development of sex organs, bone and muscle mass, and libido. In some medical conditions, such as polycystic ovary syndrome (PCOS), androgens can be overproduced, leading to symptoms such as acne, hair growth, and menstrual irregularities.