In polycystic ovarian syndrome (PCOS), luteinizing hormone (LH) levels are elevated, while follicle-stimulating hormone (FSH) levels are often low. Because FSH aromatizes androgens to estrogen, low FSH will cause androgens to increase. Low levels of FSH and high androgens keep the follicle from maturing & prevent ovulation. Hypogonadism is significantly more rare, and while extreme stress and poor nutrition may inhibit ovulation, in the United States PCOS is the leading cause of anovulation (failure to release an ovule from the ovary). 

Dehydroepiandrosterone (DHEA), an endogenous steroid hormone that is a precursor for both estrogen and testosterone, is synthesized from pregnenolone in the gonads, the adrenal glands, and the brain.

The most abundant circulating steroid hormone in the human body is Dehydroepiandrosterone (DHEA). DHEA is a precursor to several important sex hormones including testosterone and estrogen. It also functions as a neuroactive steroid.

The hormone that is secreted by the corpus luteum in order to prepare the endometrium for implantation of a fertilized ovum is progesterone. Progesterone prevents the constriction of blood vessels to the endometrium, which in turn prevents the shedding of the endometrial lining (menses). It also alters the endometrium, converting it to it's secretory phase in preparation for implantation.

Normal FSH values for a menstruating adult female are . A FSH of  would be considered normal in a premenarchal female, while normal FSH after menopause can range from .

In a menstruating woman, follicle-stimulating hormone stimulates the maturation of follicles in the ovary. Rupture of the mature follicle and formation of the corpus luteum are both stimulated by lutenizing hormone (LH). The uterus itself does not contain follicles.

In an adult male, normal FSH can range from . It may be slightly lower in children. Follicle-stimulating hormone is released from the anterior pituitary gland; its target is the testes.

In a healthy adult male, follicle stimulating hormone stimulates the Sertoli cells of the testes to produce androgen-binding protein, it stimulates primary spermatocytes to undergo meiosis, and triggers the initiation of spermatogenesis.

Luteinizing hormone stimulates the production of estrogen by the ovary, triggers the release of the mature egg during ovulation, and then stimulates the ruptured follicle to develop into the corpus luteum, the structure responsible for providing progesterone to the endometrium in preparation for implantation, if a pregnancy were to occur. 

In a menstruating female, LH values can vary widely during the menstrual cycle. It is its highest at the peak of the menstrual cycle  and lowest during the luteal phase of the menstrual cycle .