Hormone Health


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In the last 50 years or so, the introduction of the pill, hormone replacement therapy (HRT), pesticides and other oestrogen mimics has caused the fine balance between oestrogen and progesterone to be disrupted. Sheila LM Gibson MD BSc MFHom explains the roles of these hormones in the body and how an imbalance can result in a range of modern maladies

Prior to the middle of the twentieth century, menopausal and other gynaecological problems were largely unknown. However, in the past 30-40 years, the prevalence of premenstrual syndrome (PMS), menopausal flushing and sweating, fibroids, endometriosis, infertility, breast cancer and ovarian cysts and tumours has risen alarmingly.

The increased incidence of these diseases has occurred in parallel with the increasing use of pesticides and herbicides in agriculture and of the contraceptive pill and HRT in medicine. The functions and interactions of oestrogen and progesterone are largely misunderstood by both the general public and the medical profession. A brief outline is therefore appropriate.


Three main oestrogens are produced by the ovaries; oestrone, oestradiol and oestriol. Oestrone and oestradiol are interconvertible and oestriol, the gentlest of the three, is synthesised from oestrone. The oestrogens dominate in the first two weeks of the menstrual cycle and their function is to build up a fresh lining, the endometrium, in the uterus after the previous menstrual shedding, to proliferate the cells lining the vagina and to increase vaginal mucus production which helps to protect the vagina during sexual intercourse. The oestrogens also stimulate the growth of breast tissue.

At puberty it is the oestrogens which stimulate the growth and development of the breasts, vagina, uterus and fallopian tubes in girls. They contribute to the production of the female body shape by fat accumulation and are responsible for the growth of pubic and auxiliary hair and pigmentation of the nipples and areolae.



Follicle stimulating hormone (FSH) from the pituitary gland initiates the development of a number of ovarian follicles each month, following the end of menstruation. These mature over the next 10-12 days and usually only one ruptures to liberate its ovum or egg. The other developing follicles then regress, and the follicle which ovulated becomes a corpus luteum and begins the production of progesterone in amounts of up to 20-30mg a day. At this point oestrogen levels begin to fall so that, where the oestrogens are dominant in the first half of the menstrual cycle, progesterone becomes dominant in the second half. Progesterone’s function is to mature the secretory endometrium prepared by the oestrogens, and to halt the proliferation and initiate maturation of the breast tissue. If fertilisation of the ovum does not take place, progesterone levels fall after about two weeks. The drop in both oestrogens and progesterone triggers the next menstrual shedding, and the cycle begins again.

In the non-pregnant state, oestrone and oestradiol are produced in the ovary in microgram amounts from cholesterol via pregnenolone or progesterone and oestriol is present only in traces. Oestradiol is the oestrogen with the greatest stimulatory effect on the breasts and oestriol the least. During pregnancy, the placenta becomes the major source of both oestrogens and progesterone, and placental oestrogen, which is largely oestriol, is made from dehydroepiandrosterone (DHEA) rather than from progesterone which is necessary in its own right. Both oestriol and progesterone are produced in large amounts in pregnancy, and both are sexually neutral.

From the reproductive point of view the oestrogens create the proliferative endometrium, stimulate breast tissue and decrease libido. Progesterone, on the other hand, maintains the secretory endometrium, protects against fibrocystic breasts and improves libido. It is also essential for the survival of the embryo and foetus. Without it no pregnancy could be carried to term.



Oestrogens tend to increase body fat, cause salt and water retention, may cause depression and headaches, interfere with thyroid hormone function, increase blood clotting and reduce the tone of the blood vessels, impair blood sugar control, reduce cellular oxygen levels, tend to cause loss of zinc and retention of copper and slightly impair the activity of the osteoclasts (the cells which break down old bone).(1)

Progesterone helps the body to use fat for energy, and is a natural diuretic and antidepressant. It aids the function of the thyroid hormone, normalises blood sugar levels and cellular oxygen levels, restores optimal zinc and copper levels and normalises blood clotting. It also stimulates the osteoblasts (bone building cells) and helps to prevent both endometrial and breast cancer. With the exception of the precursor molecules pregnenolone, 17-hydroxypregnenolone, DHEA and androstenediol, it is a precursor of all the other steroid hormones including the oestrogens. It is, in effect, the mother hormone, both from the point of view of maintaining and supporting pregnancy and from the point of view of the other steroid hormones and their many metabolic functions.(1)

It is thus apparent that progesterone and the oestrogens have opposing functions in the body - see table 1 opposite – Comparison of oestrogen and progesterone. They do, however, facilitate each other’s actions by stimulating each other’s receptor sites.



Oestrogen Effects

Oestrogen Effects
Creates proliferative endometrium
Stimulates breast cell proliferation
Increases body fat
Retains salt and water
May cause depression
Interferes with thyroid hormone
Increases blood clotting
Decreases libido
Impairs blood sugar control
Decreases zinc and increases copper
Reduces cellular oxygen levels
Increases risk of endometrial cancer
Increases risk of breast cancer
Reduces osteoclast function
May cause headaches

Progesterone Effects

Maintains secretory endometrium
Protects against breast fibrocysts
Helps to burn fat for energy
Natural diuretic
Natural antidepressant
Aids action of thyroid hormone
Normalises blood clotting
Restores libido
Normalises blood sugar levels
Normalises zinc and copper levels
Restores normal cellular oxygen levels
May prevent endometrial cancer
Helps to prevent breast cancer
Stimulates osteoblast function
May help prevent headaches
Necessary for survival of embryo and foetus
Precursor of other steroid hormones

Source: Adapted from Lee, J R. Natural Progesterone: the multiple roles of a remarkable hormone.(1)



Under normal circumstances, as long as a woman continues to menstruate, the oestrogens and progesterone are kept in balance and the adverse effects of oestrone and oestradiol are kept in check. However, in the last half century, there has been an increasing use of pesticides and other biocides, petrochemicals and other industrial chemicals and solvents which now pollute the environment to a degree not previously experienced. All these substances are oestrogen mimics and are therefore classed as xeno-oestrogens, foreign oestrogens. They have the potential to upset the delicate oestrogen-progesterone balance and cause the symptoms of oestrogen dominance. The oestrogen-only contraceptive pill, which works by suppressing ovulation, not only increases oestrogen levels, but also prevents ovarian progesterone production since no corpus luteum is formed.

The symptoms of oestrogen dominance, such as weight gain, fluid retention, discomfort in the breasts or cystic breasts, depression, headaches and mood swings therefore begin to manifest, leading to PMS, fibroids, endometriosis and general gynaecological dysfunction. It is therefore not surprising that the increasing use of the pill is paralleled by the increasing frequency of these gynaecological disorders.
By the time a woman reaches menopause, oestrogen dominance has often been present for years. It is a drop in oestrogen below a critical level that signals the cessation of the periods. If there is insufficient oestrogen to proliferate enough endometrium, there is little tissue to shed and no period will occur. It is at this stage that hormone replacement therapy (HRT) is usually advised.

The original HRT was, once again, oestrogen-only and was therefore incapable of addressing the oestrogen-progesterone imbalance. It often had the effect of making the symptoms worse. When the combined pill, or combined HRT was introduced, it was unfortunately, a progestogen, not progesterone that was used.


The progestogens, known as progestins or gestagens in the US, are a class of synthetic hormones manufactured by drug companies from progesterone. The definition of a progestogen is any substance other than progesterone itself, which will maintain the secretory endometrium. This is the only property which most of them have in common with progesterone. They are produced by altering, adding to or removing the side chains of the progesterone molecule, thus creating an unnatural substance but one which can, unlike progesterone, be patented. Since minor alterations to the side chains of progesterone and the other steroids can produce greatly different metabolic effects, the progestogens have little else in common with progesterone and often produce unpleasant or even serious side effects.

Progesterone can be converted by the body into other steroid hormones. The progestogens are end-molecules and cannot be transformed into anything else. Since they cannot be metabolised, they can cause metabolic blocks. Much confusion exists in the minds of both the general public and the medical profession about progesterone and the progestogens and the side effects of the latter are often attributed to progesterone. An example of this is a recent report in the British Medical Journal(2) which claimed that progesterone was a risk factor for breast cancer, when in fact progesterone helps to protect against breast cancer. Reference to the original article(3) revealed that the report was a false interpretation of an American trial which showed that progestogens, not progesterone, increased the breast cancer risk.


A question that is often asked is: if progesterone production largely ceases at menopause, while oestrogen production continues, albeit at a lower level, how is it that our ancestors did not suffer from menopausal problems, PMS, breast and uterine cancer and osteoporosis?

Part of the answer lies in the fact that our ancestors were not polluted with pesticides, petrochemicals and other xeno-oestrogens, nor did they use the pill or HRT. Another aspect is that they ate fresh, organically grown vegetable foods, locally produced, harvested when ready and eaten within a short time of harvesting. Nowadays most of our plant foods are grown chemically, picked unripe, transported long distances and possibly stored for some time before they reach the shops or the supermarkets.

Plants, in addition to being a source of calories, provide us with many nutritive substances including glycosides, saponins, bioflavonoids, vitamins, minerals and plant hormones such as the phytosterols. These nutrients tend to be synergistic and help us to maintain metabolic balance. While present in many fresh, ripe or mature plant foods, they are largely lost with storage, and especially with food processing. Devitalised processed and junk foods lack these essential compounds.

Many of the medicinal herbs which have been used down the centuries contain these valuable nutrients. Phytosterol-rich foods include sage, red clover, sarsaperilla, liquorice root, alfalfa, hops, rhubarb root, wild yam, yarrow, dandelion, ginseng, blackcurrant leaf buds, vitex agnus castus (Chaste tree), saw palmetto, black cohosh and dong quai.4 Bioflavonoids, good sources of which are cherries, grapes and citrus fruits, have weak phyto-oestrogenic activity.4 Phyto-oestrogens can help to restore hormone balance by attaching themselves to oestrogen receptors thereby blocking both oestrogen itself and the xeno-oestrogens.


While it is possible, by avoiding the pill and HRT, and by paying careful attention to diet and the consumption of hormone balancing plants, to recreate the good health of our ancestors, this is not an easy option for many hard-pressed, busy working women. A simpler answer is to resort to supplementation of the missing hormone, that is, natural progesterone, to recreate the balance.

Soya and Mexican wild yam products that can be purchased from health food stores, although often marketed as such, do not contain natural progesterone, nor are they converted into progesterone in the body. The confusion seems to be linked to the phyto-oestrogens that these plants contain, which are believed to account for the excellent support these plants provide to menopausal and younger women.

However natural progesterone can be produced from wild yam or soya, in a laboratory, by converting the plant sterols into human-identical hormones: oestrogen, progesterone or testosterone. At present, this product is only available on prescription and is administered as a transdermal cream, which is rubbed into the skin twice daily.

For pre-menopausal women it is used from day 12 to day 26 of the period, day 1 being the first day of the menstrual flow. For post-menopausal women the recommendation is to use it for 3 weeks out of 4. Cycling of the hormone prevents the progesterone receptors from becoming saturated. Progesterone can be helpful in many gynaecological problems. Pre-menopausally it is most frequently used to treat PMS, fibroids, migraines, depression, endometriosis (there are special instructions for its use in this condition), pelvic inflammatory disease (PID), recurrent abortions and miscarriages, menstrual irregularities, anovulatory periods, fibrocystic breast disease and ovarian cysts.

Menopausally and post-menopausally, flushing, sweating and mood swings are natural progesterone’s commonest indication. It can also help with vaginal dryness (sometimes a little oestriol may also be necessary), depression, migraines, fibrocystic breasts, low libido and low energy states. It also helps to prevent breast,(5,6,7) ovarian(8) and uterine cancer,(1) heart disease(9,10) and osteoporosis.(1) It can, however, when first being used by menopausal women who have not been producing progesterone for some time, briefly increase the oestrogenic effects because of its stimulating action on the oestrogen receptors. This is usually remedied by increasing the dose of progesterone used, until the system once more achieves balance.

It may be surprising how many apparently different conditions can be helped by natural progesterone. The reason lies in its key role in harmonising steroid metabolism, recreating hormone balance generally and improving immune system function. It is simple to use and free of unwanted side effects. It is far kinder to the body and much more environmentally friendly than both the pill and HRT for which it is a safe, effective and natural alternative.


Lee, J R. Natural Progesterone: The multiple roles of a remarkable hormone. Jon Carpenter Publishing, Oxon, 1999.
Josefson, D. Women taking combination HRT are at greater risk of breast cancer. BMJ, 2000, 320. 333.
Schairer, C Lubin, J, Troisi, R, Sturgeon, S, Brinton, L and Hoover, R. Menopausal oestrogen and oestrogen-progestin replacement therapy and breast cancer risk. JAMA, 2000, 283, 485-491.
Kenton, L. Passage to Power. Vermilion, London, 1996.
Bergkvist, L, Adami, H-O, Persson, I, Hoover, R and Schairer, C. The risk of breast cancer after oestrogen and oestrogen-progestin replacement. N Engl. J. Med., 321, 293-297.
Henderson, B E, Ross, R K, Pike, M C and Casagrande, J T. Endogenous hormones as a major factor in human cancer. Cancer Res., 1982, 42:32.32 – 32.39.
Hrushesky, W J M. Breast cancer, timing of surgery, and the menstrual cycle: call for prospective trial. J. Women’s Health, 1996, 5. 555-556.
Rodriques, C, Calle, E E, Loates, R J, et al. Oestrogen replacement therapy and fatal ovarian cancer. Am. J. Epidemiol. 1995, 141, 828-834.
Williams, J K, Honore, E K, Washburn, S A and Clarkson, T B. Effects of hormone replacement therapy on reactivity of atherosclerotic coronary arteries in cynomolgus monkeys. J. Am. Coll. Cardiol., 1994, 24, 1757-1761.
Miyagawa, K Rosch, J Stancyk, F and Hersmeyer, K. Medroxyprogesterone interferes with ovarian protection against coronary vasospasm. Nature Medicine, 1997, 3, 324-327.

Sheila Gibson is a medically qualified doctor and homeopath. She worked in toxicology and medical genetics before joining the Glasgow Homeopathic Hospital in 1976.


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