Estrogens are steroid hormones that play numerous roles in the female body. They are not “essential” in the absolute sense, but they are crucial for the optimal functioning of many tissues. While they regulate the menstrual cycle, their influence extends far beyond reproduction: estrogens contribute to the health of bones, the heart, the brain, metabolism, and muscle tissue.

During perimenopause and menopause, the progressive decline in estrogen levels can lead to visible and invisible changes that affect quality of life. Understanding how these hormones work helps to interpret what happens in the body during this natural transition.

What are estrogens and why are they important

In women of reproductive age, estrogens are produced mainly by the ovaries. After menopause, ovarian production decreases sharply, and most estrogens derive from the peripheral conversion of androgens in adipose tissue, with a minor contribution from the adrenal glands.
Among the different forms of estrogens (estradiol, estrone, estriol), estradiol (E2) is the most biologically active during the fertile years.

Estrogens act by binding to specific receptors (ERα and ERβ) distributed throughout the body, including bone, muscle, heart, blood vessels, and brain. Through these interactions, they modulate gene expression involved in multiple cellular processes. As a result, they help maintain bone strength, preserve muscle mass, protect the cardiovascular system from events such as heart attacks and strokes, and support cognitive function and mood balance.

When estrogen levels fall, as in menopause, this communication network weakens. The body may then show a range of symptoms as hot flashes, irregular sleep, weight gain, fatigue, or difficulty concentrating. These are not trivial discomforts but physiological responses to profound hormonal changes.

How estrogens influence different systems of the body

Bone and muscle health

Estrogens regulate bone remodeling by inhibiting osteoclastogenesis (via decreased RANKL and increased OPG) and promoting osteogenesis through the Wnt/β-catenin pathway. Their deficiency accelerates bone mineral loss and increases the risk of fracture.
Low estrogen levels can also contribute to a reduction in muscle mass (sarcopenia) and a shift in body fat distribution (increased visceral fat). However, the exact relationship between estrogen deficiency, muscle metabolism, and strength remains less clearly defined than for bone.

Cardiovascular system

Estrogens exert vascular and lipid effects: they promote vasodilation (for example, by increasing nitric oxide production), may reduce arterial stiffness, and influence lipid metabolism.
However, their “protective” effect on cardiovascular disease is not consistent across all clinical contexts. A review published in Maturitas (2024) reported that cardiovascular risk rises in the early postmenopausal years, but this cannot be attributed solely to estrogen decline, rather to a combination of metabolic, hormonal, and age-related factors.

Brain and cognitive function

In the brain, estrogens have complex, multi-level effects. They enhance synaptic plasticity, regulate neuronal growth and survival, and modulate key neurotransmitters such as serotonin, dopamine, and acetylcholine.
These mechanisms support memory, attention, processing speed, and mood regulation. When estrogen levels drop during the menopausal transition, many women experience concentration problems, mental slowing (“brain fog”), mood swings, irritability, and increased vulnerability to anxiety or depressive symptoms.

Recent research, including studies published in Frontiers in Neuroscience (2024), confirms the role of estradiol in maintaining brain plasticity and cognitive performance. However, despite promising findings, controlled clinical trials have not yet demonstrated a definitive preventive effect of hormone therapy on cognitive decline; therefore, it is not currently recommended for this purpose in the absence of other indications.

Metabolism and energy

Estrogens influence body weight regulation and fat distribution by modulating glucose use and insulin sensitivity, key factors in metabolic health.
Their reduction is associated with increased visceral fat and potential changes in energy metabolism.
A study in Nature Metabolism (2023) suggested a possible link between estrogen deficiency and reduced mitochondrial activity in experimental models. The clinical implications for fatigue and physical performance in humans, however, require further confirmation.

Urogenital system

Estrogens maintain the structure and function of vaginal, urethral, and bladder tissues, ensuring elasticity, vascularization, and hydration through local estrogen receptors.
When levels decrease, tissues become thinner and less lubricated, leading to dryness, irritation, and painful intercourse.

This condition, known as Genitourinary Syndrome of Menopause (GSM), may include vaginal dryness, irritation, dyspareunia, urinary urgency, and increased susceptibility to urinary infections.
According to EMAS guidelines, local estrogen therapy should be considered the first-line treatment for GSM, provided no contraindications exist, within a personalized clinical evaluation.

What happens when estrogen levels decline

Estrogen deficiency affects the entire body. Common consequences include bone and muscle loss, slowed metabolism, weight changes, redistribution of fat, and worsening of the lipid profile.
Sleep disturbances, mood changes, memory and concentration issues, and genitourinary discomfort are all linked to this hormonal shift.
While the intensity varies among individuals, these effects represent a natural adaptation of the body to a new hormonal phase.

Strategies to protect hormonal health

Hormone replacement therapy (HRT)

HRT can relieve menopausal symptoms and prevent complications associated with estrogen deficiency, such as osteoporosis and vasomotor symptoms.
According to the North American Menopause Society (NAMS, 2024), hormone therapy is most beneficial when started within about ten years of menopause or before age 60. It should always be individualized according to age, time since menopause, and cardiovascular and oncologic risk profile.
Dosage and route of administration (oral, transdermal, or vaginal) must be defined in consultation with an experienced physician.

Non-hormonal approaches

When HRT is not indicated or not desired, evidence-based alternatives include:

• A Mediterranean diet rich in fiber, vegetables, and healthy fats
• Regular physical activity, including strength and resistance training
• Adequate intake of calcium, vitamin D, and high-quality protein
• Stress-management techniques such as mindfulness or yoga
• Local treatments for GSM
• Non-hormonal medications for symptom control and prevention of osteoporosis, cardiovascular, or metabolic complications

An integrated approach combining lifestyle measures and, when appropriate, targeted medical support can improve wellbeing and reduce symptoms.

When to consult a specialist

Consult a gynecologist or endocrinologist if menopausal symptoms significantly interfere with quality of life, to develop a personalized plan that includes hormonal assessment, laboratory testing, and tailored therapeutic strategies.

However, medical evaluation should not focus only on symptom relief: menopause represents a key opportunity for preventive medicine.
Reduced estrogen levels progressively increase the risk of osteoporosis and fractures, cardiovascular disease, cognitive decline, and muscle loss.

Timely medical attention not only improves current wellbeing but also helps plan effective interventions to protect bone, heart, brain, and mood health, slowing some of the physiological processes of ageing.

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You can book a consultation with Dr. Silvia Accornero directly on Pausetiv, by following this link.

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