Every woman is endowed at birth with a set number of eggs within each ovary. As a woman ages, her ovaries become depleted of eggs. At this point ovulation may become erratic. This results in a lowered production of progesterone during the luteal phase. At this stage a woman is considered peri-menopausal. As the oestrogen production increases, the progesterone production is not keeping up. This imbalance between the oestrogen and progesterone results in the classic symptoms of fluid retention, breast tenderness, weight gain, irritability, headaches, and sleeplessness. At this stage many women experience irregular bleeding episodes that may be heavy and unpredictable.

Most women reach peri-menopause between the ages of 40 and 52, the average being around 45. But there have been cases of women experiencing symptoms of peri-menopause as early as their mid-30s.

Clinically women going through this transitional phase can be divided in to 3 distinct groups:

  • Those that have severe symptoms of peri-menopause – a mild menopause often follows this.
  • Those that have very few peri-menopausal symptoms – they drop heavily into menopause and suffer significantly from oestrogen and progesterone deficiency.
  • Those that have very mild symptoms of both oestrogen and progesterone deficiency.

The women who experience severe symptoms of peri-menopause are often more sensitive to the presence of oestrogen. They are classified as “oestrogen dominant”. A potential theory is that the cell receptors that are specific for oestrogen are overly sensitive, resulting in an over-reaction to oestrogen. Progesterone can act as a competitive antagonist with oestrogen for these receptors and will block or dampen the effect of oestrogen on the receptors. So, when progesterone declines during peri-menopause, this oestrogen dominance becomes more significant. The receptors respond to even a low level of oestrogen, so these women are less likely to experience symptoms of oestrogen deficiency during menopause.

The second group of women who have severe symptoms of menopause have oestrogen and progesterone receptors with a “normal” degree of sensitivity. Once the levels of these hormones decline, the individual experiences the absolute deficiency of these hormones – there is no back up from sensitive oestrogen receptors.

There is no definite literature that explains the third group of women, but it could be hypothesized that women who do not experience symptoms of menopause or peri-menopause, will likely have cell receptors that are hyper-sensitive to both oestrogen and progesterone, so even when their hormone levels are low, the cell receptors are still able to transmit a message to the cell, avoiding the symptoms of deficiency. So, these women will remain relatively symptom free throughout this transitional process.

A vital understanding for treatment at this stage is that we cannot treat all women with a one-size- fits-all treatment. Therapies that counteract the oestrogen dominance, including progesterone supplementation are the most effective means of treating symptoms of peri-menopause. But each woman’s needs are highly specific and these needs change over the course of her transition. As a result, treatment during this time tends to be more dynamic and compounded bio-identical hormones offer the flexibility of individualizing treatment.