Progesterone – The Great Mediator

Progesterone’s role

The chemical structure of progesterone

Progesterone is estrogen’s partner. It is secreted primarily in the ovary after ovulation and is responsible for promoting implantation of the embryo and maintaining pregnancy. It is the major hormone of pregnancy. During a woman’s menstrual cycle estrogen causes the uterine endometrium to grow and prepare for a pregnancy. Progesterone comes in about mid-cycle and says “OK, that’s enough”, and modulates the building effect of estrogen and finishes preparation for gestation and then hangs around in high levels if implantation occurs to make sure everything stays calm and supportive for the next nine months. Estrogen builds, makes things grow, makes us excited, sometimes irritable, and repairs tissues.  Progesterone is like the grandmother who comes in and calms everything down. It modulates not only endometrial growth but also decreases breast tissue proliferation. It has a calming, anti-anxiety effect on the nervous system through stimulation of GABA receptors, especially when given orally.

Estrogen – A Hormone Much Maligned

Estrogen – The female hormone

The chemical structure of estrogen

Estrogen is a hormone familiar to most everyone.  It is what makes us female.  It makes women have soft skin and curves, high lilting voices, and breasts.  It has over 400 functions in the body and has a powerful emotional, psychological, and physical effect on our body.  It is produced primarily by a woman’s ovaries and a small amount is produced by the adrenal glands.  At menopause, a precipitous fall in estrogen (as well as progesterone, which we will discuss later) leads to changes in the body that can cause symptoms that most people are familiar with such as hot flashes, insomnia, mood swings, vaginal and genital atrophy, and depression as well as an overall decline in general well being.

Hormone Misinformation

The recent New York Times article (click here) regarding the Million Women Study and hormone replacement therapy (HRT) adds another layer of confusion for women.  I would like to provide some clarification by looking at the medical literature and analyzing what it shows.

First, some caveats:

1. The medical literature and many analysts do not distinguish between synthetic and bio identical hormones.  They are not biochemically the same and have different effects on the body, which has been documented in many studies.
2. Premarin is a synthetic equillin estradiol made from pregnant mares’ urine.  Estrace, topical estradiol systems, and compounded estradiol are made from soy and are biochemically identical to the main estrogen, estradiol, which is made by your body.