Which hormone is considered the most important male sex hormone?

• A. Estrogen
• B. Testosterone
• C. Oxytocin
• D. Progesterone

Answer: (B)

Testosterone is the principal male sex hormone (an androgen). It is mainly produced in the testes and drives the development of male reproductive organs before birth, as well as the secondary sexual characteristics that emerge at puberty—like a deeper voice, facial and body hair, increased muscle mass, and stronger bone density. It also promotes sperm production by acting on the Sertoli cells and interacts with other reproductive hormones to regulate fertility. Males do have small amounts of estrogen and progesterone, but these hormones are not the primary drivers of male sexual development; estrogen mainly comes from the aromatization of testosterone and helps with bone health, while progesterone plays a different role more prominent in females. Oxytocin is a neuropeptide involved in social bonding and reproductive behaviors, not a primary sex hormone. Therefore, testosterone best fits as the most important male sex hormone.