Oestrogen Dominance in Perimenopause: What Does It Actually Mean?

Oestrogen dominance describes a hormonal pattern in which oestrogen has a greater effect relative to progesterone.

This can occur because oestrogen exposure is high, because progesterone production has fallen, or because both changes are occurring together.

During perimenopause, relative oestrogen dominance is particularly common. Oestradiol can remain active and fluctuate considerably while progesterone production becomes less consistent as ovulation changes.

Oestrogen exposure is also affected by the way the body produces, metabolises and recirculates oestrogen. Adipose tissue can produce oestrogens, the liver metabolises them, and the gut influences how much processed oestrogen is eliminated or returned to the circulation.

These processes are relevant because they affect the total amount of oestrogenic activity the tissues are exposed to.

During perimenopause, oestrogen does not decline in a steady line. Oestradiol can fluctuate considerably and can still be relatively high during some cycles.

At the same time, ovulation becomes less consistent.

The timing and combination of symptoms provide useful clinical information.

Heavier bleeding, increasing breast tenderness and stronger premenstrual symptoms occurring alongside changing cycles are more informative than one symptom considered alone.

Persistent or unusually heavy bleeding should still be assessed appropriately rather than automatically attributed to hormones.

Oestrogen stimulates growth of the lining of the uterus, known as the endometrium.

After ovulation, progesterone helps regulate that lining.

When ovulation becomes less consistent during perimenopause, the normal progesterone rise after ovulation can be reduced or absent. The endometrium can therefore receive oestrogen stimulation without the same progesterone response that would occur during a regular ovulatory cycle.

This contributes to the heavier, longer or more unpredictable bleeding many women notice during perimenopause.

Oestrogen does not come exclusively from the ovaries.

Adipose tissue , body fat , contains an enzyme called aromatase. Aromatase converts certain androgen hormones into oestrogens.

Before menopause, the ovaries are the main source of circulating oestradiol. Following menopause, ovarian production falls substantially and adipose tissue becomes an increasingly important source of peripheral oestrogen production. [3]Source

Nutrition can influence several stages of oestrogen metabolism. The most useful choices are those with a plausible or demonstrated relationship with bowel elimination, gut metabolism or oestrogen metabolites.

Oestrogen metabolites are partly eliminated through the bowel.

Fibre supports bowel regularity and alters the intestinal environment in which hormone metabolites are processed.

Human research has found that higher-fibre dietary patterns can affect circulating oestrogen concentrations, although the effect differs according to the type of fibre used. [7]Source

Useful sources include:

• lentils
• beans
• chickpeas
• oats
• whole grains
• vegetables
• berries
• nuts and seeds

Broccoli, Brussels sprouts, cabbage, cauliflower and kale contain glucosinolates.

These produce compounds including indole-3-carbinol, which has been studied for its effects on pathways involved in oestrogen metabolism.

Include cruciferous vegetables several times across the week rather than relying on concentrated “oestrogen detox” supplements.

Alcohol has a direct relationship with circulating oestrogen.

A recent review found that acute alcohol intake can temporarily increase estradiol and that regular consumption of around one or more alcoholic drinks per day is associated with higher estradiol concentrations. [10]Source

Reducing regular alcohol intake therefore has a clearer biological rationale in an oestrogen-focused plan than many products marketed as hormone detoxes.

Adipose tissue produces oestrogens through aromatase.

Magnesium is not an oestrogen-lowering treatment, but it remains an important mineral in midlife nutrition.

Magnesium contributes to normal energy-yielding metabolism, normal functioning of the nervous system, normal muscle function and reduction of tiredness and fatigue, when the product meets the required conditions for those authorised health claims.

A convenient magnesium formulation to support normal energy metabolism, nervous-system function and muscle function as part of your daily nutrition.

Magnesium product details will be linked here when available.

Oestrogen dominance does not simply mean that a woman’s oestrogen level is high.

During perimenopause, the most common pattern is oestrogen continuing to fluctuate while progesterone production becomes lower or less consistent as ovulation changes.

Higher oestrogen exposure can also be influenced by peripheral production in adipose tissue and by the way oestrogen is metabolised, eliminated and recirculated through the liver and gut.

Assessment therefore focuses on three areas:

oestrogen production
progesterone production
oestrogen metabolism

Veerpal Sandhu, MPharm, IP
Advanced Clinical Pharmacist Prescriber | Women’s Health & Menopause

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2. Prior JC, Hitchcock CL. The endocrinology of perimenopause: need for a paradigm shift. Frontiers in Bioscience (Scholar Edition). 2011;3:474–486.

3. Lee MJ, Den Hartigh LJ. Metabolic impact of endogenously produced estrogens by adipose tissue in females and males across the lifespan. Frontiers in Endocrinology. 2025;16:1682231.

4. Stanczyk FZ. Metabolism of endogenous and exogenous estrogens in women. Journal of Steroid Biochemistry and Molecular Biology. 2024;242:106539.

5. Palacios S, Martin J, Hernandez I, Orozco R. Estradiol loss, the estrobolome, and midlife symptoms: what the gut microbiome adds to menopause care. Menopause. 2026.

6. Precision Analytical Inc. DUTCH Complete and DUTCH Sex Hormone Metabolites. Current laboratory test information and sample reporting documentation.

7. Rose DP, Goldman M, Connolly JM, Strong LE. High-fiber diet reduces serum estrogen concentrations in premenopausal women. American Journal of Clinical Nutrition. 1991;54(3):520–525.

8. Brooks JD, Ward WE, Lewis JE, et al. Supplementation with flaxseed alters estrogen metabolism in postmenopausal women to a greater extent than does supplementation with an equal amount of soy. American Journal of Clinical Nutrition. 2004;79(2):318–325.

9. Chang VC, et al. Effect of dietary flaxseed intake on circulating sex hormone levels among postmenopausal women: a randomized controlled intervention trial. Nutrition and Cancer. 2019.