About Progesterone

What is progesterone?

Progesterone is a steroid hormone, often referred to as a sex hormone. The word ’steroid’ is a generic name for dozens of body regulators (hormones) made from cholesterol.

Cholesterol, the basic building block for the steroid hormone, gives them all a similar structure. Switch a few atoms around and the role of the hormone can change dramatically. Without sufficient cholesterol, we can’t make sufficient steroid hormones. Some of the more familiar steroids are estrogen, progesterone, testosterone, the corticosteroids, and DHEA.

Progesterone is one of two main reproductive hormone groups, the other being the estrogens, made by the ovaries of menstruating women. It is primarily a hormone of fertility and pregnancy.

The three major functions of progesterone in our body are:

• to promote the survival and development of the embryo and fetus
• to provide a broad range of core biologic effects
• to act as a precursor (building block) of other steroid hormones

Progesterone is also made in smaller amounts by the adrenal glands in both sexes and by the testes in males. Progesterone is a precursor of other hormones such as estrone, estriol, estradiol, testosterone, and all the important adrenal cortical hormones.

(Printed with Permission - ‘Ask Dr Sandra Cabot Newsletter, Edition 6′)

Progesterone is also made in mammals. In fact, progesterone was obtained from the ovaries of pigs and later from human placentas. Both these methods were expensive and only yielded small quantities of progesterone - therefore uneconomical to market.

In the 1940s, however, Dr Russell E. Marker discovered a chemical process by which he could economically manufacture progesterone from saponins harvested from the Mexican Wild Yam and Soy plants.

The levels of progesterone in a woman’s body rise and fall dramatically with her monthly cycles. At ovulation, the production of progesterone rapidly rises from 2-3mg per day to an average of 22mg per day, peaking as high as 30mg per day a week or so after ovulation. After ten or twelve days, if fertilisation does not occur, ovarian production of progesterone falls significantly. It is this sudden decline in progesterone levels (as well as estrogen levels) that triggers a period/menstruation, and another menstrual cycle will begin.

If pregnancy occurs, progesterone production increases and the shedding of the lining of the uterus is prevented, preserving the developing embryo. As pregnancy progresses, progesterone production is taken over by the placenta and its secretion increases gradually to levels of 300-400mg per day during the third trimester.

If, however, a woman fails to ovulate during her cycle the result would be too little progesterone in her body, and estrogen dominates the hormonal environment. For your understanding, progesterone is manufactured by the empty sack left behind by the released egg. This sack is known as the corpus luteum. Unless ovulation takes place and the egg is released, progesterone will not be manufactured.

A fundamental key to hormone balance is the knowledge that when estrogen becomes the dominant hormone and progesterone is deficient, the estrogen can potentially become toxic to the body; thus progesterone has a balancing or mitigating effect on estrogen.

Progesterone is the body’s natural anti-estrogen.

The diagram below demonstrates what actually take place in a women’s body during her 28 cycle.

(Printed with Permission - ‘Ask Dr Sandra Cabot Newsletter, Edition 3′)

What is a progesterone receptor?

It is a physical structure on the cell membrane that attracts the progesterone molecule / hormone, and responds to its effect at that receptor site. Because there are literally hundreds of progesterone receptors (sites) throughout the body, progesterone will have a major impact on your body as each receptor relays a specific message.

Why do women need progesterone?

Progesterone has a comprehensive role in a woman’s body. And when levels drop, your body is going to react in a big way. We now know that if we allow estrogen to dominate the hormonal environment, there is significant risk of breast cancer and reproductive cancer. So one of progesterone’s most important roles is to balance or negate the effects of estrogen.

At menopause, a women’s estrogen level will drop by 40-60% (or can be lower in cases involving thin women). Just low enough to stop the menstrual cycle. Progesterone levels, however, may drop close to zero in some women.

This wouldn’t have bothered a woman at the turn of the 20th century who rarely lived beyond her reproductive years. But these days a woman can expect to live to 85 years and beyond. She needs to give some thought to how she’s going to rejuvenate her ‘ageing’ endocrine system. Natural hormone replacement will become a vital anti-ageing tool for both men and women, and progesterone supplementation is a good place to start.

At menopause, the adrenals and other organs take over the manufacturing of hormones, particularly testosterone and estrogen, and some progesterone. However, in cases of adrenal exhaustion and other health problems, the body often cannot compensate adequately, thus causing further hormonal havoc to the body.

Progesterone is a precursor (or building block) to many other steroid hormones such as cortisol, testosterone and estrogen (estriol, estradiol, estrone). Because it is a modulator, its use can greatly enhance overall hormonal balance. Progesterone supplementation will stimulate bone building and help protect against osteoporosis, not overlooking the numerous positive roles it plays in the body. For women who suffer hormonal imbalance but are not necessarily menopausal, progesterone is equally important. Even young women in their 20s and, on occasions, teenagers may need progesterone if they are not ovulating regularly and present with an array of estrogen dominant symptoms.

During pregnancy, rising progesterone levels prevent the premature shedding of the uterine lining (pro-gestation). If progesterone levels drop due to inadequate progesterone production, then a premature delivery could result, or bring about a miscarriage in the early trimesters.

In fact, feedback from women suggests progesterone is very effective in opposing estrogen dominance symptoms of all ages.

Progesterone benefits include the following:

• Maintains the secretory endometrium
• Protects against fibrocystic breasts
• Helps use fat for energy
• It is a natural diuretic
• Natural anti-depressant / mood enhancer
• Facilitates thyroid hormone action
• Normalises blood clotting
• Restores sex drive
• Normalises blood sugar levels
• Normalises zinc and copper levels
• Restores proper cell oxygen levels
• Prevents endometrial (uterine) cancer
• Helps prevent breast cancer
• Simulates osteoblast for bone building
• Restores normal vascular tone
• Necessary for the survival of the embryo
• Precursor of corticosteroids and other hormones
• Modulates other hormones helping to restore balance
• Promotes sleep
• May help improve libido
• Contributes to reducing anxiety and panic attacks
• Reduces estrogen dominance symptoms

Why do men need progesterone?

Progesterone in men is vital to good health. It is the primary precursor of their adrenal cortical hormones and testosterone. Men synthesise progesterone in smaller amounts than women do but it is still important.

The metabolic actions of the prostate gland are determined in large part by hormones, especially estradiol, progesterone, and testosterone, which are made by the testes. These, in turn, are mediated by pituitary hormones, especially FSH and LH, just as ovarian function is women is.

Both the prostate gland and the uterus develop from the same embryonic cells, and both respond to the same hormones - estrodiol, progesterone, and testosterone.

Adding progesterone back into the body helps restore normal inhibition of 5-alpha-reductase, thus preventing testosterone from changing into dihydrotestosterone (DHT), which stimulates proliferation of prostate cells.