Which hormone is the primary male sex hormone?

• A. Estrogen
• B. Progesterone
• C. Growth Hormone
• D. Testosterone

Answer: (D)

Testosterone is the primary male sex hormone. It is produced mainly in the testes and drives the development of male reproductive organs before birth, as well as the male secondary sexual characteristics that appear at puberty—such as a deeper voice, facial and body hair, and increased muscle mass and bone density. It also supports sperm production and sexual function. Other hormones like estrogen and progesterone are typically associated with female reproductive biology, though they are present in males too in smaller amounts and serve other roles. Growth hormone influences general growth and metabolism rather than defining male sexual characteristics, so it isn’t the primary male sex hormone.