Difference Between Progesterone and Estrogen

Progesterone vs Estrogen

A Regulatory chemical produced by an endocrine gland or an organ, that travels through the blood stream to affect specific cells or an organ in a different place in the body is defined as a hormone. Progesterone and estrogen are the two types of female sex hormones that the ovaries begin to secrete at puberty and the placenta secretes during pregnancy. Basically these hormones are responsible for producing sexual characteristics, developing reproductive system, and maintaining pregnancy in females. Both these hormones are steroid compounds and are transported in the blood as small, hydrophobic molecules by binding to a serum globulin. Like all other steroid hormone, estrogen and progesterone readily diffuse across the cell membrane.


There are six different estrogens in the female body, but only three of them are in substantial amounts. They are estradiol, estrone, and estriol. Estrogen promotes and maintains female organs and secondary sexual characteristics in females. It also enhances protein anabolism, promotes thinning of cervical mucus, inhibits ovulation, and prevents postpartum breast pain. In addition, estrogen maintains the elasticity of the urogenital structure and stimulates growth of axillary and pubic hair and pigmentation of the nipple and genitals. Estrogen also helps indirectly to strengthen the skeleton by conserving calcium and phosphorus and encourage bone formation.

Estradiol is the most important estrogen hormone secreted by the ovaries, while estriol is the most abundant of three other types. Estrone is produced only during the pregnant period. During pregnancy, placenta produces estrone and maintains the uterine lining, which is helpful in protecting and nourishing the developing embryo.


Progesterone belongs to the group of progestin and involves in the female menstruation cycle, pregnancy, and embryogenesis in humans. It also helps to maintain the secondary characteristics of female. Progesterone is a steroid hormone, which is carried by blood to target cells in the body and stored in adipose tissues, in the body. Progesterone is a hydrophobic molecule and is composed of four cyclic interconnected hydrocarbons. It is mainly produced in ovaries, adrenal glands, and in the placenta (during pregnancy).

What is the difference between Progesterone and Estrogen?

• During the period of pregnancy, estrogen develops the mammary ductal system while, progesterone improves the lobular and alveolar growth.

• Estrogen stimulates formation, development and maintenance of the female secondary characteristics, whereas progesterone helps to maintain female secondary characteristics.

• Progesterone belongs to hormone group called progestin, while estrogen is considered as a hormone group. There are six types of hormones that come under the group estrogen.

• During pregnancy, placenta cannot synthesize estrogen until the development of the fetus to the point that it releases DHEA (dehydroepiandrosterone) into blood. In contrast, the placenta can synthesize progesterone soon after implantation.