FSH (Follicle stimulating hormone) and LH (Lutineizing Hormone) are usually attributed as female only hormones. But in fact they are just as present in boys as girls.

The two hormones are Gonadotropins, which means that they take action on the gonads (The primary reproductive organs) and they are both released, as you probably know, by the pituitary gland in the brain. A common misconception is that the pituitary gland is the starting point for all hormone secretion. When in fact its in the middle - a respondant: it is triggered by a hormone called GnRH, standing for gonadotropin releasing hormone, which is secreted by the Hypothalamus, which is just above the pituitary gland.

 Anyway GnRH is secreted within the brain`s of both boys and girls, and so consequently FSH and LH are secreted by the pituitary in both sexes - but they have very different affects. In girls FSH and LH are crucial for maintaining and managing the menstrual cycle. However in boys FSH is the hormone which triggers the testes to produce sperm cells, whilst LH causes testosterone to be made and secreted by the testes. Testosterone is the hormone that causes facial and bodily hair growth and muscular development, as well as accounting for male sexuality. But it does not actually cause sperm production!

This is why men who are extremely masculine, can actually suffer from infertility, because although their levels of LH are high - their FSH levels may be low, causing sperm production not to be prevalent enough to achieve fertilization.