Sex hormone combinations are products that contain more than one sex hormone, either estrogen and progestin or estrogen and androgen.
Estrogens are a group of hormones that are synthesized mainly by the ovaries and a small amount is synthesized by the testes in males and by the adrenal cortex in both sexes. The placenta produces a fairly large amount of estrogen as well. The three main endogenous estrogens are estradiol, estriol and estrone.
Progestins are a group of naturally occurring or synthetic steroid hormones. The naturally occurring progestin is progesterone, which is secreted by the corpus luteum of the ovary, the placenta and also (in small amounts) by the adrenal cortex and testes. It prepares the inner lining of the uterus for pregnancy, and if pregnancy occurs it maintains the uterus through the pregnancy and prevents ovulation by the ovaries during pregnancy.
Androgens are steroid hormones that stimulate development of male sex organs and sexual characteristics. Androgens are mainly released by the testes and small amounts are released by the adrenal cortex and ovaries.
The combinations, which have estrogen and progestin are used as birth control or to treat menopausal symptoms. Combinations with estrogen and androgen are used control menopausal symptoms.
