The hormones of the reproductive system are chemicals produced by the body that help regulate the functions of sexual development and procreation. Certain hormones — like gonadotropin-releasing hormone, follicle-stimulating hormone, and lutenizing hormone — are present in both males and females. Estrogen and progesterone, however, are the primary hormones of the female reproductive system. Testosterone, on the other hand, is the primary hormone of the male reproductive system.
One of the primary hormones of the reproductive system is gonadotropin-releasing hormone (GnRH), which is produced by the hypothalamus. Low levels of GnRH are present in the blood of children, but these increase dramatically when they are ready to start puberty. GnRH then stimulates the production of other reproductive system hormones, particularly follicle-stimulating hormone and lutenizing hormone.
Follicle-stimulating hormone (FSH) is produced by the anterior pituitary gland. In females, this hormone is partly responsible for the maturation of eggs, and it helps regulate a woman's menstrual cycle. In males, FSH aids in sperm production.
Like GnRH and FSH, lutenizing hormone (LH) is also present in females and males, and it is produced by the anterior pituitary gland as well. In females, LH helps stimulate ovulation and aids in releasing a mature egg. In males, however, this hormone causes the testes to begin sperm production.
Estrogen and progesterone are the two main reproductive hormones of females. Often considered to be the main female hormone, estrogen is primarily produced by the ovaries. It is responsible for the thickening of the uterine wall, or endometrium, in anticipation of fertilized egg implantation and pregnancy. Estrogen is also responsible for the secondary sex characteristics of females, like breasts, and it helps keep bones strong.
Progesterone production in the ovaries is typically stimulated by the presence of LH, and along with estrogen, it helps prepare the endometrium for pregnancy. During a pregnancy, this hormone is also responsible for keeping the uterine lining healthy. Progesterone production in the ovaries ceases once the placenta becomes developed enough to produce it.
Although it is found in small amounts in females, testosterone is one of the most important hormones of the male reproductive system. High levels of this hormone begin around puberty, and testosterone is responsible for the secondary sex characteristics of males, including body hair and deep voices. This hormone is produced in the testicles, and its main responsibilities include regulating a man's sexual drive and sperm production.