Low oestrogen: symptoms, causes and treatment options

Key takeaways

• Low oestrogen affects multiple body systems, including bone health, cardiovascular health, brain function, and mood, which is why the symptom picture is so broad and varied.
• For women aged 45 and over with typical symptoms, UK clinical guidelines state that a blood test is not required to begin treatment. Diagnosis is based on symptoms and adopting a holistic view.
• HRT is the most effective treatment for low oestrogen and its consequences. NICE updated its guidance in 2024 to state that HRT is "unlikely to increase or decrease overall life expectancy" for most women, which is reassuring when considering if HRT is the right option for you.

What oestrogen actually does, and why its decline matters so much

Oestrogen is produced primarily by the ovaries and acts on receptors throughout the body. Its effects extend well beyond reproduction.

In the skeleton, oestrogen helps keep the natural process of bone renewal under control by slowing down bone breakdown. When oestrogen levels fall, this control is reduced, so bone can be lost more quickly. In the cardiovascular system, oestrogen supports blood vessel flexibility, helps regulate cholesterol, and has a protective effect on the arterial walls. In the brain, oestrogen influences the production and regulation of serotonin, dopamine, and other neurotransmitters involved in mood, memory, and cognitive function. In the skin, it supports collagen production, hydration, and the integrity of the tissue lining the vagina and urinary tract.

A 2024 systematic scoping review published in Maturitas, drawing on longitudinal evidence, confirmed that menopausal symptoms are significantly associated with future cardiovascular disease, psychiatric disorders, diabetes, and reduced bone mineral density. This is the evidence base for the principle that addressing low oestrogen matters beyond symptom relief: the health consequences accumulate over time and are meaningful.

Understanding what oestrogen does makes the symptoms of its decline considerably easier to make sense of.

The symptoms of low oestrogen: what women actually experience

Low oestrogen does not produce a single defining symptom. It produces a cluster of effects across multiple body systems, which is part of why it can take so long to recognise.

Vasomotor symptoms

Hot flushes and night sweats are the most widely recognised symptoms of declining oestrogen. They occur because oestrogen helps regulate the hypothalamus, the brain region that controls body temperature. When oestrogen falls, this regulation becomes unstable. Vasomotor symptoms affect many, but not all women during the menopausal transition and can range from mild and occasional to frequent and significantly disruptive.

Sleep

Sleep disruption is closely linked to vasomotor symptoms (night sweats that wake women repeatedly) and to direct hormonal effects on sleep architecture. Among Voy members receiving menopause treatment, 71% reported improved sleep (presented at The Menopause Society 2025, forthcoming in Climacteric).

Cognitive function

Around two-thirds of women report cognitive concerns during the menopause transition, including memory lapses, word-finding difficulties, and reduced concentration, according to the most current review of this topic published in The Lancet Obstetrics, Gynaecology and Women's Health in 2026. This is commonly referred to as brain fog. Prospective studies indicate these changes are objectively measurable, not simply perceived. 73% of Voy members reported improvement in brain fog after starting treatment (presented at The Menopause Society 2025, forthcoming in Climacteric).

Mood

Anxiety, low mood, irritability, and tearfulness are all associated with oestrogen's influence on neurotransmitter regulation. A 2025 NHS-affiliated scoping review in Frontiers in Reproductive Health found that perimenopausal and early postmenopausal women are two to four times more likely to experience a significant depressive episode. 83% of Voy members reported improved mood and emotional symptoms after starting treatment (presented at The Menopause Society 2025, forthcoming in Climacteric).

Genitourinary symptoms

Vaginal dryness, discomfort, reduced lubrication, pain during sex, increased urinary frequency, and urinary urgency and recurrent UTIs are all caused by declining estrogen's effect on the tissue lining the vagina and urinary tract. The clinical term is genitourinary syndrome of menopause (GSM). These symptoms are extremely common and very effectively treated, yet many women do not realise they are hormonal in origin and therefore do not raise them with a clinician.

Libido and energy

Reduced sexual desire and persistent fatigue are associated with low oestrogen, but it is worth noting that testosterone also declines during the menopausal transition and contributes significantly to both of these symptoms. This is covered in more detail below.

Physical symptoms

Joint pain, headaches, changes in skin texture, and increased susceptibility to skin reactions are all associated with declining oestrogen. Menopause does not produce a consistent, recognisable pattern for every woman, and the combination of symptoms experienced varies considerably.

“An important nuance: during perimenopause, oestrogen fluctuates rather than simply declining steadily. Symptoms may be unpredictable, varying week to week or even day to day, which can make them harder to attribute to a single hormonal cause.”

Katy Jackson, Clinical Director - Women's Health

The causes: why oestrogen levels fall

Natural menopause and perimenopause

The most common cause of low oestrogen is the natural menopausal transition. The ovaries gradually reduce oestrogen production, typically between the mid-40s and mid-50s in the UK. Perimenopause, which can last several years, is characterised by fluctuating oestrogen. Menopause itself (defined as 12 consecutive months without a period) marks the point at which oestrogen settles at a sustained low.

Premature ovarian insufficiency (POI)

POI occurs when the ovaries stop functioning normally before the age of 40. It affects approximately 1 in 100 women under 40, according to ESHRE 2024 guideline data. Causes include autoimmune conditions, genetic factors (including Turner syndrome and fragile X premutation), and often no identifiable cause. Women with POI face the same consequences of low oestrogen as those going through natural menopause, but at a much younger age, with additional implications for bone health, cardiovascular health, and fertility. This group is covered in more detail below.

Surgical menopause

Removal of both ovaries (bilateral oophorectomy) causes an immediate and abrupt loss of oestrogen, regardless of age. This is covered in detail in our article on medically induced menopause.

Medical treatments

Chemotherapy, pelvic radiotherapy, and GnRH agonist medications (used to treat endometriosis, uterine fibroids, and some cancers) can all suppress or eliminate ovarian oestrogen production. The effect may be temporary or permanent depending on the treatment, dose, and age.

Hypothalamic amenorrhoea

In some women, very low body weight or very high levels of exercise can suppress the hormonal signals that tell the ovaries to produce oestrogen. This is known as hypothalamic amenorrhoea, and it affects women across age groups, often presenting as absent or very irregular periods alongside low oestrogen symptoms. If this applies to your situation, speaking to a specialist is the right first step.

Other causes

Pituitary disorders can disrupt the hormonal signals that regulate oestrogen production. Certain autoimmune conditions affecting the ovaries can reduce function. Thyroid dysfunction can interact with and compound oestrogen-related symptoms - declining oestrogen levels can affect thyroid-binding proteins, which may require adjustment of thyroid medication.

How low oestrogen is diagnosed, and what the tests actually show

One of the most practically important things to know about diagnosing low oestrogen is this: according to NICE NG23 (2024), women aged 45 and over with typical menopause symptoms do not need a blood test to confirm the diagnosis. Menopause is a clinical diagnosis, based on age and symptoms. Waiting for a blood test, or being told one is needed before treatment can be discussed, is not in line with current UK clinical guidance.

Blood tests are appropriate when the picture is less clear: when a woman is under 45 and menopause is suspected, when another condition might be contributing to symptoms, or when monitoring the effectiveness of existing treatment.

When oestrogen tests are used, oestradiol (the main form of oestrogen produced by the ovaries) is the primary measurement. FSH (follicle-stimulating hormone, which rises as the ovaries produce less oestrogen) is also commonly included. SHBG (sex hormone binding globulin) and FAI (free androgen index) provide additional context about how hormones are being processed.

An important caveat: during perimenopause, oestrogen levels fluctuate significantly. A single reading may not reflect the full picture. A result showing normal oestrogen does not rule out perimenopause if symptoms are consistent with it and HRT can still be considered despite a "normal" hormone profile.

Voy's Women's Midlife MOT Blood Test measures 16 biomarkers including oestradiol, FSH, SHBG, FAI, and a full cholesterol panel, for women aged 40 and over who want a comprehensive view of their hormonal and metabolic health. It is not a prerequisite for a consultation, but it can add useful information, particularly when monitoring the effects of treatment over time.

The long-term health picture: why treatment matters beyond symptoms

Treating low oestrogen is not only about managing symptoms. Sustained oestrogen deficiency carries cumulative health consequences that are worth addressing proactively.

Bone health

Oestrogen is the primary regulator of bone turnover in women. When it declines, bone loss accelerates, and the risk of osteoporosis and fracture rises significantly. A 2025 systematic review in Cureus confirmed that HRT produces greater improvements in bone mineral density than exercise therapy alone, with reduced fracture risk at the hip and vertebrae. The Frontiers in Reproductive Health 2025 review confirmed that declining oestrogen can cause bones ot lose strength more quickly, which can increase the risk of fractures.

Cardiovascular health

Before menopause, women typically have a lower incidence of cardiovascular disease than men of the same age. But this changes after menopause; where risk increases as oestrogen levels decline. The Maturitas 2024 scoping review confirmed cardiovascular disease is positively associated with menopausal symptoms and symptom severity. Cardiovascular disease is the leading cause of death in women globally.

Cognitive health

The Lancet 2026 review confirmed that objectively measurable cognitive changes occur during the menopausal transition for a significant proportion of women. The relationship between oestrogen, brain health, and timing of hormonal support is an active area of research and the causes of cognitive symptoms during menopause are likely to be multifactorial. Metabolic health

Research consistently associates premature or early menopause with elevated risk of type 2 diabetes and metabolic syndrome. The metabolic consequences of sustained low oestrogen compound over time.

The point of this section is not to alarm but to motivate. These are manageable conditions when addressed proactively. They are harder to address when low oestrogen has been left unmanaged for years.

Hormone Replacement Therapy: the most effective treatment for low oestrogen

HRT replaces the oestrogen the ovaries are no longer producing. For women with a uterus, a progestogen is added to protect the womb lining. For women who have had a hysterectomy, oestrogen alone is typically prescribed.

Routes of delivery

Transdermal HRT (patches, gels, or sprays applied to the skin) is the form favoured by NICE NG23 (2024) for most women, because it does not carry the same VTE (blood clot) risk as oral tablets. Oral tablets are an alternative for women who prefer them or for whom transdermal is not suitable. The 2025 narrative review in the International Journal of Molecular Sciences confirmed that transdermal oestrogen is the favoured evidence-based approach.

What NICE says about safety

NICE updated its guidance in 2024 to state that HRT is "unlikely to increase or decrease overall life expectancy" for most women. This reflects the totality of the evidence: while HRT is associated with a small increased risk of some conditions in some formulations, it is associated with meaningful benefits across other domains. For most women with low oestrogen symptoms, the benefits of HRT outweigh the risks.

For a detailed look at HRT risks and benefits, including the evidence on breast cancer risk and the oral vs transdermal distinction, see our article on HRT: what the evidence actually shows.

88% of Voy members felt more hormonally balanced at three months, compared to 62% receiving standard care (presented at The Menopause Society 2025, forthcoming in Climacteric). That gap reflects the difference a personalised, specialist-led approach makes. 93% reported improvement in overall quality of life.

Testosterone: the hormone that often gets forgotten

Oestrogen is not the only hormone that declines at menopause. Testosterone also falls, and its decline contributes meaningfully to symptoms that oestrogen-focused treatment may not fully resolve: reduced libido, persistent fatigue, low motivation, and reduced muscle strength.

Testosterone is often associated with men, but it is an important hormone for women too. The ovaries produce testosterone alongside oestrogen, and surgical removal of both ovaries causes an abrupt loss of ovarian testosterone production alongside oestrogen.

Testosterone treatment plans (available as Testogel, Androfeme, or Voy's Testosterone cream) are part of Voy's menopause service. A testosterone blood test within the last three months is required before a prescription can be issued. Testosterone may help with libido, energy, and motivation, though individual responses vary and results are not guaranteed. Your specialist can assess whether it is appropriate for your situation.

Vaginal oestrogen: addressing genitourinary symptoms specifically

Vaginal oestrogen is a topical treatment that helps restore vaginal tissue, making it thicker, more elastic, and more hydrated. It acts locally with minimal systemic absorption and is therefore suitable for many women who cannot or do not wish to take systemic HRT.

NICE NG23 (2024) specifically recommends that vaginal oestrogen should be offered to women with genitourinary symptoms. It is effective for vaginal dryness, discomfort, pain during sex, and urinary symptoms associated with the menopausal transition. These symptoms are very common, often undertreated, and very effectively addressed with local treatment.

Vaginal oestrogen can be prescribed alongside systemic HRT or independently. Voy offers vaginal oestrogen as part of its comprehensive menopause care.

When HRT is not suitable: other options

Some women cannot take systemic HRT, or choose not to. The following options have clinical evidence or NICE approval.

Fezolinetant and Elinzanetant

Fezolinetant and Elinzanetant are non-hormonal prescription medicines for moderate to severe vasomotor symptoms in women for whom HRT is unsuitable. Fezolinetant was approved by NICE in 2026. Elinzanetant has been approved by the MHRA (The Medicines and Healthcare products Regulatory Agency) but as of July 2026 is awaiting approval by NICE . They work by blocking the neurokinin 3 receptor pathway in the brain that drives hot flushes. They are the first non-hormonal option to receive NICE approval specifically for vasomotor symptoms, and its availability is a meaningful development for women who cannot take hormonal treatment.

CBT (Cognitive Behavioural Therapy)

CBT is recommended by NICE for vasomotor symptoms, mood-related symptoms, and sleep disruption associated with menopause. It has a meaningful evidence base in its own right and is not a second-best option. It can be used alongside or instead of hormonal treatment. Voy offers structured CBT as part of its comprehensive menopause care.

SSRIs and SNRIs

Antidepressants including venlafaxine and paroxetine have evidence for reducing vasomotor symptom frequency. NICE NG23 recommends they are not offered as a first-line option for vasomotor symptoms alone. They may be appropriate in specific clinical contexts, particularly when mood symptoms are prominent.

Lifestyle measures

Regular exercise, dietary changes (particularly the Mediterranean dietary pattern), reduction in alcohol, and sleep hygiene measures are all supportive. They are not curative for oestrogen deficiency and should not be positioned as substitutes for clinical treatment where treatment is appropriate. They work best as part of a broader care plan.

Low oestrogen in younger women: premature ovarian insufficiency

POI is not a variation of menopause that happens earlier. It is a distinct condition with its own clinical profile, its own risks, and its own urgency.

POI affects approximately 1 in 100 women under 40, though some recent analyses suggest the prevalence may be higher. Many causes remain unidentified. Symptoms are the same as menopause, but occurring in a woman who expected decades more of normal ovarian function: that discrepancy carries significant psychological weight. The 2025 NHS-affiliated scoping review noted that over 60% of women with POI exhibit clinically significant anxiety or depression.

The ESHRE 2024 guidelines and BMS 2024 consensus statement both strongly recommend HRT for women with POI, at least until the age of natural menopause. The long-term health risks of sustained low oestrogen from a young age, including accelerated bone loss, cardiovascular risk, and cognitive effects, are more pronounced than in natural menopause and require proactive management rather than a watchful waiting approach.

POI can also affect fertility. The picture varies individually. A specialist is best placed to discuss your specific situation and options, which may include fertility preservation and referral to a reproductive specialist.

If you have received a POI diagnosis or suspect you may have it, the urgency of specialist assessment is higher than for women experiencing natural menopause at the expected age. This is not a situation for self-management.

Getting the right support

Low oestrogen is a medical situation that deserves a clinical response: not a supplement, not a decision made on the basis of a single blood test result, and not a ten-minute GP appointment where there is no time to take a full history.

Voy's menopause consultations are 45 minutes with BMS-trained (British Menopause Society) specialists. That time allows for a proper assessment of your symptoms, your medical history, any relevant test results, and the full range of treatment options, from systemic HRT to testosterone, vaginal oestrogen, CBT, and nutritional support. The treatment plan is built around your individual picture, not a generic protocol.

"For the first time in 24 years, I felt safe. I felt truly listened to." That is Charlotte, a Voy member, describing her first consultation. Twenty-four years of symptoms that had not received an adequate response. That experience is not unusual, and it should not be the norm.

93% of Voy members reported improvement in overall quality of life after starting treatment (presented at The Menopause Society 2025, forthcoming in Climacteric). That outcome requires more than a prescription: it requires a treatment plan that accounts for everything declining oestrogen is doing, not just the most visible symptoms.