Frequently Asked Questions



Please note that the information given below is for information and educational purposes only. Consult a doctor for advice on your individual health requirements.

What is progesterone?

Progesterone is the hormone produced by the female ovary after ovulation. It supports and maintains pregnancy but has other important functions too. It is the precursor to other vital hormones. It is needed to ‘oppose’ oestrogen, that is to keep it in balance. Progesterone receptors are found in brain cells, in nerve sheaths and in bone cells, indicating that progesterone is involved in their function. It also appears to be involved in a range of other biological functions.

It is important to understand that a woman's ovaries only make progesterone when she ovulates. There is growing evidence that many of today's women are failing to ovulate regularly, particularly after the age of thirty-five. A woman may bleed regularly every month but not be ovulating or producing progesterone.

After menopause, the female body makes close to zero progesterone, in fact the male body makes more. On the other hand, women continue to make oestrogen throughout their lives, even if they have had their ovaries removed. Oestrogen is made by the adrenal glands and in the body fat and the muscle cells. The fall in oestrogen production at menopause is only about 40%. Some obese women produce more oestrogen after menopause than thin women do in their pre-menopausal years!

The theoretical basis for HRT is the idea that if women suffer problems during the menopausal years then it must be because they have an oestrogen deficiency. The fact that they have a complete loss of progesterone at menopause has been forgotten. It is Dr John Lee’s belief, based on 20 years of clinical practice with progesterone, that it is progesterone that most women need, not oestrogen (although some women, he says, do also benefit from a very low dose of oestrogen in addition).

There are three different kinds of oestrogen naturally made by the body (oestradiol, oestrone and oestriol), but only one form of progesterone. In the last forty years progesterone has largely been forgotten and synthetic versions of it, called progestagens, have been prescribed instead. Many researchers and doctors have used the name progesterone to mean both progesterone itself or one of the synthetic progestagens. This has led to a great deal of confusion. In all literature provided by the Natural Progesterone Information Service the name progesterone refers only to the natural female hormone.

What are progestagens?

Progestagens (called progestins in America) are synthetic hormones that are similar but not identical to progesterone. Because a natural substance such as progesterone cannot be patented, it is generally not profitable for a pharmaceutical company to obtain a licence to produce it as a medicine (to license a medicine can cost millions of pounds). But if that natural substance is slightly changed it can then be patented and licensed as a medicine.

However such a substance is no longer ‘natural’ to the body. Even a tiny change from the natural hormone can result in considerable side effects.

All known progestagens cause particularly undesirable consequences in the body - as can be seen by the long list of side effects listed in medical textbooks. This is because progesterone has a very central role to play in making other hormones. It is like trying to build a jigsaw around the wrong piece. Unfortunately for many years progesterone has been ‘lumped in’ with the progestagens and many doctors have assumed that progesterone also causes these serious side effects. Evidence is now clearly emerging that this is not the case.

What is natural progesterone?

Natural progesterone is the hormone produced by the ovaries (and also by the male body). This hormone can also be made in the laboratory from plant sources such as Mexican yam.

The result is identical in every way to the hormone produced by the body and is called natural progesterone because it is identical to the hormone the ovaries make.

Natural progesterone is not difficult to make. The process has been known since the 1930s. It is true that the natural progesterone now available on prescription has been synthesized – the body also synthesizes the progesterone it makes – but it is not synthetic, that is it is not unnatural. It is the body-identical hormone, progesterone.

Because natural progesterone cannot be patented, for financial reasons it is almost impossible for a natural progesterone cream to be licensed as a medicine. Any progesterone creams sold in this country must be sold as ‘unlicensed medicines’ and they are only available on prescription.

What are women prescribed natural progesterone for?

Natural progesterone is prescribed for the many symptoms of progesterone deficiency, in particular for menopausal problems and osteoporosis. It can also be used in the treatment of PMS, low libido, fibrocystic breast disease, uterine fibroids, endometriosis, cervical hyperplasia and ovarian cysts and can be helpful in some cases of infertility. For further information see Natural Progesterone, the Multiple Roles of a Remarkable Hormone by John R Lee MD and other books and papers available through the Natural Progesterone Information Service.

How safe is natural progesterone?

Since this is the hormone that nature itself produces, when it is only given in the dose that nature herself supplies, it is considered to be extremely safe. During the second half of her cycle a woman's ovaries produce approximately 20mg of progesterone a day. But during pregnancy the level of the progesterone produced by the placenta rises to more than 300mg. Since nature considers it safe to expose women and their babies to such very high levels of progesterone, this is an indication of the high safety level of natural progesterone. The mistaken belief that progesterone can cause difficulties is based on confusion between the normal function of progesterone and the toxic side effects of synthetic progestagens. In fact, many progestagens are closer in function to testosterone or oestrogen. The reports of scientific research using synthetic progestagens confirm that these synthetic hormones have a devastating effect on the body. But there is no research which shows that natural progesterone, when given at the normal physiological level, is not perfectly safe to use where appropriate.

Why is natural progesterone often used as a cream?

Independent laboratory tests show that progesterone absorbs very well through the skin (as do other hormones, which is why hormone patches are common). It is absorbed into and stored by fat cells which then supply a regular small dose into the bloodstream. When it is given by mouth a very much larger dose has to be given because a lot of it will be destroyed by the liver as soon as it is absorbed. Dr Lee believes a good progesterone cream should supply about 20-30mg of progesterone a day. This is the amount that healthy ovaries produce during the luteal phase (the second half of the menstrual cycle).

Progesterone is also available in the UK as suppositories, which can be used either anally or vaginaIly. However, the dose of progesterone supplied by suppositories currently available is 10-20 times higher than the ovaries would normaIly supply. Dr John Lee’s research and clinical results are based or prescribing progesterone at the normal physiological level and no higher.

What do you do if you’re already on HRT and want to switch?

HRT normally comes in two parts one supplying oestrogen, the other progestagen.

1) Oestrogen

Do not stop taking the oestrogen component of HRT right away! Withdrawing from oestrogen overnight could trigger severe menopausal symptoms. It is important that, guided by a doctor, a woman withdraws from the oestrogen component of HRT over a period of at least three to nine months. Dr Lee generally recommends that patients reduce their oestrogen dose by half immediately and continue to reduce it every cycle or two until no longer needed. If hot flushes or vaginal dryness continue to occur, then a minimum dose of oestrogen should perhaps be continued.

2) Progestagen

If you and your doctor have decided to opt for the natural hormone, then in Dr Lee’s experience you can stop taking the progestagen immediately and start using natural progesterone, in the normal physiological dose (20 to 30mg) right away.

Do women need to take oestrogen as well?

In Dr John Lee’s clinical experience (unless they are in the process of changing from HRT) most women do not need to supplement with oestrogen in addition to progesterone. He reccomends that menopausal women try using progesterone alone for at least three months before deciding whether oestrogen should also be used. Dr Lee maintains that there are only two reasons why oestrogen might be prescribed in addition to progesterone – if a woman is either suffering from vaginal dryness or hot flushes that are not completely controlled by progesterone – and he believes women should try progesterone alone for 3-4 months first.

In most cases oestrogen will not be needed. Since oestrogen can be toxic, only the smallest possible amount should be used , much less than is normally prescribed for HRT.

If I need oestrogen which kind is best?

Dr Lee believes that the oestrogen patch is the safest method because the dose can be controlled precisely. He suggests reducing the dose even further by sticking the patch over a hole cut in a sticking plaster so that only part of the patch is in touch with the skin. This is a method developed by his patients to find the smallest dose of oestrogen that would balance their symptoms. He does not recommend combined natural progesterone and oestrogen creams because it is not possible to vary the dose of the oestrogen. If you do use oestrogen cream you should be aware that the less well known form, oestriol (or estriol), although safer as far as cancer is concerned, is not advisable while trying to reverse osteoporosis.

Are there any side effects with natural progesterone?

If a woman is not making her own progesterone then supplying it at the level that the ovaries would normally produce does not cause side effects. However, in the first few weeks of starting to use the natural hormone, a few women may temporarily experience an exaggeration of their previous ‘oestrogen dominance’ symptoms such as breast tenderness, headaches or depression. This is rare and generally passes after the first month, taking longer in a very few cases. It probably happens because progesterone sensitizes the body's oestrogen receptors (and vice versa), making the oestrogen in her body more effective. This is why a woman on HRT must reduce her oestrogen intake by half as soon as she begins to use progesterone, as the oestrogen will have a far greater effect. It is more likely to occur if a woman has a build up of oestrogen, whether from chemical pollutants (many of which are oestrogenic), from the Pill or HRT, or because she has not been producing her own progesterone (which normally keeps oestrogen in check) for a considerable time.

Women who run into this problem sometimes find it helpful to increase their progesterone for a while to bring their oestrogen into balance more quickly. Other women have found it more comfortable to cut back and build up slowly. A very small number of women find progesterone is not for them.

How do women feel on natural progesterone?

Most women feel very comfortable on natural progesterone. Most shed their menopausal symptoms – hot flushes, mood swings, etc. They tend to feel energised. They may lose some weight, especially around hips and thighs. Water retention is also generally reduced. Headaches, especially if they are related to your cycle, are often much helped. A lot of women report feeling more 'up' in mood (remember that progesterone is very high in late pregnancy, a time when many women feel good). Cravings may also be reduced. Many women experience reduced breast tenderness and, given time, can get rid of breast cysts. We also know from Dr Lee’s published results that bone density increases. We have heard of women being freed from the pain that osteoporosis can inflict. However, although most women's experience is very positive, there are women who find it difficult, especially at first, and there are a few women that it doesn’t suit at all.

Can progesterone help prevent or reverse osteoporosis?

Over the course of the last twenty years, Dr Lee has collected the bone mineral density scans of thousands of his patients, showing quite objectively that their bone density increased significantly. In a published study in Medical Hypotheses (35, 314,318, 1991) he reported that a group of 66 patients increased their bone density over three years by an average of 15%. We are already hearing of women in the UK with very encouraging increases in their bone density. But remember that there are other factors needed to build bone, including calcium, magnesium, vitamin D and vitamin C. Weight bearing exercise is also important. Progesterone does seem to help with the pain of osteoporosis and may help relieve pain in some cases of arthritis. See Natural Progesterone, The Multiple Roles of a Remarkable Hormone by John Lee MD.

Can progesterone help PMS?

Yes, in many cases it can be very helpful, especially if you know you're not ovulating. (One way to test this is to take your temperature each morning when you wake. If you notice a distinct temperature rise around the middle of the month you have probably ovulated). You can also have your progesterone levels tested (see below) around day 21 of your cycle (counting the first day you bleed as day 1), to see if you are making enough. If it is low then supplemental progesterone will probably be very helpful. If you are a young woman you may only need to use progesterone for a few months and then quit; in Dr Lee’s experience this can sometimes bring a woman’s hormone function back into balance. For PMS, use progesterone in the second half of every cycle only. It sometimes helps to start with a very low dose on day 14 and increase it each day so that you take most of your month's allowance in the last few days.

Women with PMS may also need a supplement that contains magnesium, zinc, vitamin B6, vitamin B3, vitamin C and biotin, because these nutrients are needed to make the prostaglandin PGE1 which helps relieve conditions like PMS. The herbs dong quai, white peony and black cohosh as well as the fatty acid GLA, found in starflower or evening primrose oil, are also helpful.

Can it help endometriosis?

Natural progesterone can be used to prevent menstrual bleeding, which triggers the pain of endometriosis although it is not the cause. In his book Natural Progesterone, The Multiple Roles of a Remarkable Hormone Dr Lee explains how, by applying sufficient progesterone from day 10 to day 26 of the menstrual cycle, bleeding and pelvic pain will be considerably reduced and, over a period of time, the body has a chance to recover. None of his patients following this regime have had to resort to surgery. This must be done under the supervision of a doctor.

Can natural progesterone be used after breast cancer?

There is evidence that if surgery for breast cancer is performed in the second half of a woman's cycle (when her progesterone is highest) she has less chance of metastases (the development of further cancer). This is part of the evidence that shows that progesterone is protective against cancer. A 30 year retrospective study at the prestigious Johns Hopkins University in America found that women who were progesterone deficient had 5.4 times more incidence of breast cancer and 10 times more deaths from cancer of all kinds (Am J Epidem. 114, 2, 1981). This again indicates the protection that progesterone gives against cancer. Finally, French studies (Fertility and Sterility 63: 785-91) show that progesterone actually slows the rate of mitosis (cell division) in breast duct cells. Based on this evidence and on his many years of experience with his own patients, Dr Lee believes that it is protective for a woman to use progesterone after cancer (applied in rotation around the body as indicated before, not applied to the breasts). If a woman is taking Tamoxifen, which is itself a weak oestrogen, progesterone can help protect her from any risk involved in this treatment. The above information is for interest only and in any post-cancer treatment a woman should be advised by her doctor.

Can I take use natural progesterone after a hysterectomy?

The standard medical view is that progesterone is only needed for pregnancy and to protect the endometrium or womb. However, it is now known that progesterone has many other functions in the body. Progesterone receptors are found in the brain, in nerve sheaths, and in the cells which make new bone to name a few. In addition there is growing evidence that progesterone can protect against breast cancer. So a woman who has had a hysterectomy may well want to talk to her doctor about taking progesterone to help protect her bones and her breasts, as well as to smooth her way through the menopause.

What about facial hair?

Progesterone is a precursor to other vital steroid hormones in the body. When women’s bodies don’t make progesterone their adrenal glands make the hormones they need from a different precursor called DHEA. This pathway leads to the formation of more androgenic or male hormones (which women make anyway to a small extent) and a woman may develop a hairy chin or legs and lose some hair on her head in typical male pattern baldness as a result. Supplementing with natural progesterone may help this problem over time.

What about fertility?

Progesterone can help some forms of infertility, particularly those due to low progesterone in the second half of the cycle. See Dr Lee’s books.

What about men?

Progesterone is not a feminising hormone and will not harm men. In fact their bodies make it too. Although men do not seem to suffer deficiency of this hormone as women do, it has been reported to help restore male libido. It may also help certain cases of men suffering from osteoporosis.