Understanding relative oestrogen excess

Relative oestrogen excess is not a case of having ‘too much oestrogen’, but refers to the ‘relative’ excess of oestrogen in the body in relation to other hormones.

When discussing relative oestrogen excess, we examine factors that increase exposure to oestrogen throughout life, and the propensity to have more oestrogen floating around more often for varying reasons.

This abundance of oestrogen compared to other hormones is referred to as ‘relative’ because it’s describing oestrogen levels that are high relative to other hormones. It may not mean that there is high oestrogen.

There is no one test that can determine whether someone has relative oestrogen excess, but we can look at a range of factors to try to figure it out. Relative oestrogen excess may not need treatment as such, but too much oestrogen, relative or not, can present some problems

Factors that can increase exposure to oestrogen throughout our lives

  • Age of first period (menarche)
  • Age of menopause
  • Obesity (but not being just overweight – fat cells facilitate the conversion of androgens (like testosterone) to oestrogen, thus increase overall oestrogen levels but not other hormones)
  • Hormone therapies containing oestrogen
  • Environmental oestrogens (called xenoestrogens, found in plastic water bottles, takeaway containers, water supply)
  • Unknown reasons

Causes of relative oestrogen excess

The more menstrual cycles you have, the more oestrogen you are exposed to across each cycle.

Factors that reduce total lifetime menstrual cycles include:

  • How many times you are pregnant (meaning long stretches without menstrual cycles)
  • If you breastfeed your babies (breastfeeding suppresses normal menstrual cycles due to high levels of prolactin, required to produce milk, preventing ovulation and opposing oestrogen)
  • When you got your first period
  • When you get your last period

Particularly in the western world, people have vastly different lifetime exposure to oestrogen than anyone historically. We have fewer pregnancies, decreased rates of breastfeeding, earlier onset of puberty and periods, and later menopause. These factors all overall result in more menstrual cycles and thus more oestrogen exposure.

The increase in oestrogen exposure means we are seeing the same proportional increase in oestrogen-dependent conditions such as endometriosis, fibroids, adenomyosis, endometrial and breast cancers, and fibrocystic breast disease.

Oestrogens in hormone therapies

Hormone therapy (HT) may bump up overall oestrogen exposure when given to those over age 55. Early menopause may be managed with hormone therapy to help protect bone density up to age 55, which is not believed to adversely affect health.

This age cut-off is around what would normally occur, where fertile years end with natural menopause at about age 50.

Unopposed oestrogens as a cause of relative oestrogen excess

If progesterone levels are low or absent, oestrogen has no opposite force to keep it in check, which results in unopposed oestrogen floating around your system.

Free-roaming unopposed oestrogen – which comes with a lack of its natural opposition, progesterone – occurs when ovulation has stopped for some reason or is irregular (including when nearing menopause). Once menopause occurs, the ovaries stop producing oestrogen, so there is no longer unopposed oestrogen, or much else hormonally.

Progesterone is thought to moderate the forceful effect of oestrogen on tissues.

There are a few key things observed in those not regularly ovulating (and therefore have low or absent progesterone), including the proliferation of oestrogen-responsive tissues in the breasts and endometrium.

Healthy progesterone levels appear to reduce the risk of endometriosis and fibroids.

In a fertile-aged person who has a regular, healthy menstrual cycle, the endometrium is shed at every period. All those excess endometrial cells that were produced under the influence of oestrogen disappear down the toilet.

When there is no ovulation, there is no period, so the endometrial lining stays put. Endometrial cells can overgrow and facilitate cancers. This overgrowth is why a healthy menstrual cycle and hormone therapy (for those in menopause who still have a uterus) containing both oestrogen and progesterone protects against these types of oestrogen-fed proliferation cancers.

Oestrogen given alone to those in menopause increases rates of endometrial cancer. Benign breast conditions can be worsened by relative oestrogen excess, while premenstrual syndrome (PMS) can also be aggravated. In PMS, hormone levels may not appear unusual, however, despite signs and symptoms.

How obesity affects oestrogen levels

Ovulation can be disrupted by obesity due to increased levels of a specific type of oestrogen, particularly oestrone (E1), which is produced via fat cells. The more fat you have, the more E1 is produced through the activation of an enzyme present in fat cells, aromatase, that converts androgens to E1.

This conversion is not cyclic, thus constantly exposing an obese person to a greater source of oestrogen over a longer time. Polycystic ovarian syndrome can also result in a lack of ovulation and the same types of endometrial issues.

Oestradiol (E2), by contrast, is produced by the ovaries in varying amounts across a normal menstrual cycle. Levels drop off just before a period and increase in the ramp-up to and after ovulation.

It is important to note that being classified as ‘overweight’ does not appear to cause these oestrogen-related risk factors to increase; this only occurs in those who are classified as obese. If you’re unsure, check your Body Mass Index (BMI).

How your body shape affects oestrogen levels

The distribution of fat on your body (i.e. hips, thighs, breasts, belly) determines how much sex hormone-binding globulin (SHBG) you have.

SHBG binds to oestrogen, thus determining how much free-floating oestrogen you have. The more SHBG, the less oestrogen.

How your digestive system affects oestrogen levels

Your liver, kidneys and bowel are responsible for taking oestrogen from your bloodstream (where it can fit into receptors and cause oestrogenic effects), out of your body.

Not only do you need these organs in proper working order to clear oestrogen effectively, you need a set of nutrients to make this complex chain of events occur in the order and speed in which it is designed.

Chronic constipation, for example, can result in oestrogen not being cleared out of the bowel fast enough and being recirculated, while a meat/fat-heavy diet can increase certain bacteria that ultimately cause oestrogen to be recycled.

Our diet plays an enormous role in the daily theatre of our digestive tract, with some foods known to increase and others to decrease oestrogen levels in the blood.

Low fibre, high carbohydrate, and high saturated fat diets all come with a caveat: higher risk of oestrogen-dependent problems.

Conversely, plant oestrogens can reduce circulating oestrogen effects by plugging up oestrogen receptors with a low-fi, low-risk imposter: phytoestrogens, which are about 300 times weaker than regular oestrogens.

Diet plays an incredibly interesting and important role in oestrogen levels. Read about how your diet directly affects oestrogen levels.

How our environment contributes to relative oestrogen excess

Our hormonal systems are affected by our environment in a few ways, with one important contributor to relative oestrogen excess being environmental oestrogens (xenoestrogens).

Environmental oestrogens appear from some unlikely sources, for example, a water treatment plant that pumps ‘sanitised’ water back into the water supply that still contains the oestrogen peed out by those on the pill every day. Water treatment plants don’t catch hormones.

The Thames River in London, England, for example, has some interesting creatures appearing as a result of environmental oestrogens. Oestrogens closer to our skin includes sunscreen, plastic, make-up, and a thousand other common, everyday items. We are exposed to these ingredients every day from before we are born until death.

Oestrogen metabolism – the pathway to clearance

Oestrogens are metabolised into one of two things using one of two pathways. One pathway leads to a carcinogenic, DNA-damaging, strongly oestrogenic metabolite (the C-16 pathway), while the other pathway results in a comparatively insipid metabolite (the C-2 pathway).

How or why each of us produces more or less of either metabolite is unknown, but we do know that cruciferous vegetables, coffee (but not if you are on the pill), and linseed are favourites to end up down the path of least resistance, the C-2 pathway.

What to do about relative oestrogen excess

Figuring out what’s going on with you is the first and most important step since it will dictate what treatments or management strategies are appropriate.

There are a handful of approaches taken by practitioners; however, what you are presented with will be deeply impacted by who you see – every practitioner will deal with relative oestrogen excess in a different way using their various toolkits.

It’s wise to have a variety of options, do your homework, get a second opinion, and evaluate the risks and benefits of every treatment on offer. It’s important to understand that unopposed oestrogen over long periods of time, for example, if you stop getting periods and ovulating, can be risky business.

An integrative approach is a useful place to start, to ensure you get the medical tests you need with the opportunity to manage your body without unnecessary drugs or surgeries.

What your doctor will do about relative oestrogen excess

After investigations for an underlying problem, you may be offered progestogens, a synthetic form of progesterone that acts the same in terms of opposing oestrogen and flicking the switches of receptors.

Oral contraceptives may be suggested. If obesity is a factor, weight loss strategies need to be considered. Menopause may be induced if symptoms are severe. The specific causes will be individually treated.

What other practitioners may do about relative oestrogen excess

The first thing that will be evaluated will be diet and lifestyle choices, to clear out the low-hanging fruit of a diet and digestive tract that likes to cling on to oestrogen and throw it back in the ring for round two.

Focusing on oestrogen clearance is an important part of managing relative oestrogen excess, with some herbal formulas prescribed to stimulate the liver.

If you are not ovulating (in the absence of menopause), understanding why will provide other treatment strategies to overcome this. Ovulating is a necessary and natural element in managing oestrogen levels.

With food, digestion, lifestyle and ovulation taken care of, a huge step forward in reducing unfavourable oestrogens will have occurred. These changes often take some time to implement and having a knowledgable practitioner is important.


Haffner SM, Katz MS, Stern MP, Dunn JF. Relationship of sex hormone binding globulin to overall adiposity and body fat distribution in a biethnic populationInt J Obes. 1989;13(1):1‐9.

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Jessica Lloyd - Vulvovaginal Specialist Naturopathic Practitioner, BHSc(N)

Jessica is a degree-qualified naturopath (BHSc) specialising in vulvovaginal health and disease, based in Melbourne, Australia.

Jessica is the owner and lead naturopath of My Vagina, and is a member of the:

  • International Society for the Study of Vulvovaginal Disease (ISSVD)
  • International Society for the Study of Women's Sexual Health (ISSWSH)
  • National Vulvodynia Association (NVA) Australia
  • New Zealand Vulvovaginal Society (ANZVS)
  • Australian Traditional Medicine Society (ATMS)