PART 1 - Why Oestrogen Matters for Your Bones in Perimenopause

Most women expect perimenopause to bring hot flushes, sleep changes, or emotional shifts. What hardly anyone expects is this:

The bones are often the first place where hormonal changes show up – quietly, invisibly, and years before symptoms surface.

As a clinician working with women across midlife, I often see women in their forties who discover early osteoporosis “by accident” after a scan for back or hip pain. They feel surprised – even shocked – because nothing felt wrong. That’s the tricky part: bone loss is silent.

And yet, perimenopause is the exact window when your body needs the most support to keep your skeleton strong for the decades ahead.

In this 2-part article series, I’ll walk you through:

• Why oestrogen is so essential for bone health

• What actually happens to your bones in perimenopause

• What recent research (2020–2025) shows

• The steps women can take now to protect lifelong strength and mobility

Today, we begin with the foundations.

Bone Is Not a Static Structure – It’s Alive and Constantly Remodelling

Your bones may feel solid, but inside they are dynamic, metabolic, and constantly renewing themselves.

Two main types of cells are responsible for this:

• Osteoclasts – break down old bone

• Osteoblasts – build new bone

When these two work in harmony, bone stays strong and resilient.
When the balance shifts – bone density declines.

Oestrogen: The Guardian of Your Skeleton

Oestrogen plays a central role in this delicate balance. It:

• Supports osteoblasts, helping your body build new bone

• Limits osteoclast activity, preventing excessive breakdown

• Reduces inflammation, which naturally slows bone loss

• Helps the body absorb calcium and maintain healthy levels of parathyroid hormone (PTH)

In simple terms:
Oestrogen protects the structure you already have, and it keeps bone turnover steady and healthy.

As oestrogen begins to fluctuate – and eventually decline – during perimenopause, this protective effect weakens. Bone resorption (breakdown) speeds up. Formation can’t keep up. And bone mineral density begins to drop, sometimes rapidly.

This is why the few years around the final menstrual period are a critical window for bone health.

(And yes – progesterone also supports bone building by stimulating osteoblasts. It receives far less attention, but the two hormones work together beautifully. We’ll explore this another time.)

What The Latest Research Tells Us

Recent studies confirm what many women experience in clinic:

1. Hormones change first – bones respond quickly.

Large cohort studies consistently show that:

• Declining oestrogen and rising FSH and LH are strongly linked to reduced bone mineral density (BMD) during perimenopause.

In one study of over 1,500 women (Mou et al., 2025), osteoporosis rates rose sharply even before menopause was complete – highlighting how sensitive bone tissue is to hormonal withdrawal.

2. Bone loss begins earlier than most women think.

Research shows that:

• Vertebral (spinal) bone – rich in trabecular tissue – thins fastest

• Hip and long bones follow later

This is why some women in their forties have “unexpected” low bone density when scanned for unrelated musculoskeletal symptoms.

3. Hormones and metabolism interact.

Another study (Lu et al., 2025) showed that:

• Higher oestrogen and testosterone were linked to stronger bones

• Higher blood sugar was linked to lower bone density

This reinforces what many integrative clinicians see daily – bone health is not just hormonal, it is metabolic.

Perimenopause as a Turning Point

Perimenopause is not only a hormonal transition – it’s a bone transition.

But this is not a message of fear.
It’s a message of opportunity.

This is the stage of life where proactive care makes the biggest difference.
Supporting your bones in your 40s and 50s protects mobility, strength, posture, and confidence in your 60s, 70s, and beyond.

In Part 2, we’ll explore:

• What the research shows about hormone therapy, exercise, and lifestyle

• The role of nutrients and integrative care

• How to assess bone health properly (hint: it’s more than just a DEXA)

• Practical steps every woman can take in midlife and beyond

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