Oestrogen: What It Does, What Low and High Oestrogen Feel Like, and How to Support It

Oestrogen is the primary female sex hormone — and one of the most broadly influential hormones in the human body. It supports bone density, brain function, cardiovascular health, skin elasticity, gut motility, serotonin production, and the monthly cycle. It is a builder, a protector, and a regulator.

When oestrogen is in balance — rising and falling predictably across the cycle — most women feel well. When it is too low, too high, or swinging unpredictably (as it does in perimenopause), the effects are felt across every system simultaneously.

The Different Forms of Oestrogen

Oestrogen is not a single hormone — it is a family:

• Oestradiol (E2) — the most potent and active form during the reproductive years, produced primarily by the ovaries
• Oestrone (E1) — produced in fat cells and the adrenal glands, dominant after menopause
• Oestriol (E3) — produced in large amounts during pregnancy, the weakest of the three

The oestrogen that most women are thinking about when they talk about "hormonal balance" is oestradiol.

What Oestrogen Does

• Builds and maintains the uterine lining each cycle
• Supports bone density — oestrogen inhibits bone breakdown; its decline in menopause is the primary driver of osteoporosis
• Supports serotonin production — explaining why oestrogen fluctuations so directly affect mood
• Maintains skin elasticity, hydration, and collagen production
• Supports cardiovascular health — oestrogen keeps blood vessels flexible and cholesterol profiles favourable
• Supports brain function, memory, and cognitive sharpness
• Maintains vaginal tissue hydration and elasticity
• Supports insulin sensitivity
• Influences gut motility and the gut microbiome

Signs of Low Oestrogen

Low oestrogen is most common in perimenopause and menopause — but can also occur in younger women under extreme stress, with significant undereating, or with hypothalamic amenorrhoea.

• Brain fog — difficulty finding words, poor concentration, memory lapses
• Low mood or depression that feels different from situational sadness
• Low libido
• Vaginal dryness or discomfort during sex
• Hot flashes and night sweats
• Dry skin, hair thinning
• Joint aching, particularly in the morning
• Fatigue that doesn't respond to rest
• Irregular or absent periods
• Increased susceptibility to UTIs

Signs of High Oestrogen / Oestrogen Dominance

Oestrogen dominance — too much oestrogen relative to progesterone — is more common than low oestrogen in premenopausal women. It can be driven by oestrogen actually being high, or by progesterone being low, or both.

• Heavy or painful periods
• Breast tenderness before your period
• Bloating and water retention, particularly in the luteal phase
• Belly weight that won't shift
• Mood swings, anxiety, or irritability in the week before your period
• Worsening PMS
• Fibroids or endometriosis (oestrogen-driven conditions)
• Difficulty losing weight despite diet and exercise

What Drives Oestrogen Dominance

• Poor gut health — an imbalanced estrobolome reactivates used oestrogen rather than eliminating it
• Constipation — slows oestrogen elimination; daily bowel movements are essential for oestrogen clearance
• Liver burden — the liver processes oestrogen before the gut eliminates it; alcohol, processed foods, and certain medications impair this
• Xenoestrogens — oestrogen-mimicking compounds in plastics, pesticides, and some personal care products add to total oestrogen load
• Low progesterone — oestrogen dominance is relative; even normal oestrogen becomes dominant when progesterone is insufficient
• Excess body fat — fat cells produce oestrone, adding to total oestrogen load

How to Support Healthy Oestrogen Levels

Support oestrogen clearance through the gut

• Daily elimination — if you are not having a bowel movement every day, oestrogen is being reabsorbed
• 25–35g of fibre daily feeds the estrobolome and supports elimination
• Cruciferous vegetables (broccoli, cauliflower, kale) contain DIM and sulforaphane, which support oestrogen metabolism
• Flaxseeds — lignans bind excess oestrogen for elimination
• Fermented foods restore the gut bacteria that support the estrobolome

Support oestrogen clearance through the liver

• Adequate protein at every meal — the liver needs amino acids for detoxification pathways
• Reduce alcohol — it directly competes with oestrogen for liver processing
• B vitamins, particularly B6, B12, and folate — support methylation pathways essential for oestrogen metabolism
• Bitter foods — dandelion greens, rocket, lemon water in the morning — support liver function

Support oestrogen production when low

• Adequate dietary fat — oestrogen is a steroid hormone made from cholesterol; very low fat diets impair production
• Manage stress — the HPA-HPO axis relationship means high cortisol suppresses the ovarian axis and oestrogen production
• Shatavari — Ayurvedic adaptogen that supports the reproductive axis; well-studied for perimenopausal symptoms
• Phytoestrogens — flaxseeds, soy, and red clover contain plant compounds that weakly modulate oestrogen receptors; useful for some women with low oestrogen, particularly in perimenopause

Frequently Asked Questions

What does low oestrogen feel like?

Low oestrogen typically presents as brain fog, low mood, low libido, vaginal dryness, hot flashes, dry skin, joint aching, and fatigue that doesn't improve with rest. It is most common in perimenopause and menopause but can occur in younger women under extreme stress or with significant undereating.

What is oestrogen dominance?

Oestrogen dominance is a relative excess of oestrogen compared to progesterone — it can occur when oestrogen is genuinely elevated, or when progesterone is low. Symptoms include heavy periods, breast tenderness, bloating, belly weight, mood swings before your period, and worsening PMS.

Does oestrogen affect mood?

Yes — directly. Oestrogen supports serotonin production, which regulates mood, appetite, and pain sensitivity. The mood changes that occur before periods, postpartum, and in perimenopause are largely oestrogen-mediated. When oestrogen drops sharply, serotonin follows.

Can diet affect oestrogen levels?

Yes — significantly. Fibre and fermented foods support the estrobolome and oestrogen elimination. Cruciferous vegetables support liver oestrogen metabolism. Alcohol and processed foods impair clearance. Adequate fat and protein support oestrogen production when levels are low.