What Is Oestrogen Dominance?

My colleague Dame Dr Shirley Bond has given one of the best and simplest outlines of what this condition really is so I thought it would be helpful to share it with you.


The term oestrogen dominance is a term first used by the late Dr John Lee to refer to a state where oestrogen is not being balanced by progesterone in a woman’s body. This is a particular problem approaching and at the menopause, although it can occur at much younger ages.

Oestrogen is one of the two primary female hormones, the other being progesterone, and it is the increase in the levels of oestrogen at puberty that leads to the characteristic changes that take place in the body at that time

When we refer to oestrogen we are really referring to a group of the three most important and active hormones which are: oestradiol, oestrone and oestriol. The relative amounts of these three oestrogens to each other vary at different times in a woman’s life and all three are secreted in the ovaries, adrenal glands, placenta and fatty tissue.

During the reproductive years of a woman’s life oestradiol, the strong oestrogen, is being secreted in large quantities by the ovaries.

Pregnancy changes the dominant oestrogen to oestriol which is produced by the placenta.

During the Post-menopausal years the level of oestradiol decreases but the levels of oestrone and oestriol increase. At this time the oestrogen is produced by conversion of androstenedione in fatty tissue.

Why oestrogen needs to be balanced

Whatever a woman’s age may be, these oestrogens need to be balanced by progesterone to prevent the benefits of oestrogen being outweighed by its potential problems.

At the time of the pre-menopause and menopause when it is known that oestrogen levels are falling it can be difficult to understand that a situation of oestrogen dominance could be responsible for the problems that arise.

What is forgotten is that as the menopause approaches, ovulation becomes less frequent and less efficient and at the menopause it stops altogether. As a result of this, the ovary does not produce progesterone and the oestrogen is not balanced in the body.

The actual levels of oestrogen and progesterone are not important in themselves; it is the ratio of the levels of oestrogen and progesterone to each other that matter. This means you can have oestrogen dominance with both high levels of oestrogen and with low levels. It all depends on the progesterone level as this is the key factor.

Identifying Oestrogen Dominance

It is possible to diagnose oestrogen dominance for yourself. You can see from the list below that most of the effects balance each other out. If you cover up the list of progesterone effects you can see what the effects of unbalanced oestrogen are. If you are experiencing any, or all of these, then you may well have oestrogen dominance.

Effects of Oestrogen

–   Creates proliferation of the endometrium

–   Stimulates breast tissue – tenderness

–   Increases body fat

–   Fluid retention

–   Depression

–   Suppresses action of thyroid

–   Increases blood clotting

–   Decreases libido

–   Interferes with blood sugar levels

–   Reduces zinc and retention of copper

–   Reduces cell oxygen

–   Increases risk of endometrial cancer

–   Increases risk of breast cancer

–   Slows bone breakdown

Effects of Progesterone

–   Stabilises the endometrium

–   Protects the breast

–   Helps break down fat

–   Natural diuretic

–   Anti-depressant

–   Facilitates thyroid function

–   Normalises clotting mechanism

–   Increases libido

–   Stabilises blood sugar

–   Normalises zinc and copper

–   Restores cell oxygen

–   Protects the endometrium

–   Protects the breast

–   Builds up bone

Oestrogen dominance can occur at any age but it is more likely to occur in the years preceding and during the menopause. Altering your life style, eating a good wholefood diet, as well as taking herbs and nutritional supplements to restore the normal oestrogen progesterone ratio can sometimes alleviate it.

If these methods do not work it may be useful to supplement with bioidentical progesterone.

An experienced practitioner can often diagnose oestrogen dominance by listening to your symptoms and it can also be confirmed by doing a Saliva Hormone Test.