MHT and Blood Clots

Menopause, Blood Clots and HRT: Separating Myth from Evidence

One of the most common concerns I hear from women considering hormone replacement therapy (HRT) is:

"I can't take oestrogen because I'll get a blood clot."

For some women- particularly those with autoimmune conditions, clotting disorders, a family history of thrombosis, or positive antiphospholipid antibodies - this message is often delivered as an absolute rule.

The reality is more nuanced.

Not All Oestrogen Is the Same

The increased risk of blood clots is primarily associated with oral oestrogen tablets.

When oestrogen is taken by mouth, it passes through the liver before entering the bloodstream. This "first-pass" effect alters the production of several clotting proteins and can increase the risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE).

Transdermal oestrogen - delivered through patches, gels or sprays—works differently. Because it is absorbed directly through the skin, it bypasses the liver and h as little effect on clotting factors.

Multiple studies and international menopause guidelines have found that t ransdermal oestrogen does not appear to increase VTE risk above baseline levels.

Why This Matters

Many women who are denied HRT are experiencing significant symptoms, including:

• Brain fog and cognitive difficulties
• Fatigue
• Sleep disturbance
• Anxiety
• Joint and muscle pain
• Vaginal dryness
• Loss of libido
• Worsening autoimmune symptoms
• Reduced quality of life

For women with early menopause, premature ovarian insufficiency, or significant perimenopausal symptoms, avoiding all hormone therapy may carry its own health consequences, including effects on bone health, cardiovascular health and long-term wellbeing.

Individual Risk Still Matters

This does not mean HRT is risk-free.

Every woman should have an individual assessment that considers:

• Previous blood clots
• Known thrombophilia or clotting disorders
• Antiphospholipid syndrome (APS)
• Family history
• Smoking status
• Weight
• Mobility
• Long-haul travel and other risk factors

For women a t higher baseline risk , current menopause guidance generally recommends transdermal oestrogen as the preferred option, rather than automatically excluding hormone therapy altogether.

A Shared Decision

The key message is that discussions about HRT and blood clots should move beyond a simple "yes" or "no."

The question is not:

"Does this woman have any risk factors?"

The better question is:

"What is her baseline risk, how severe are her symptoms, and what is the safest way to treat her?"

For many women, especially those struggling with debilitating symptoms, a carefully considered approach using transdermal oestrogen may offer substantial benefits without significantly increasing clot risk.

The Bottom Line

Current evidence does not support treating oral and transdermal oestrogen as equivalent when it comes to blood clot risk.

While some women have an elevated underlying risk of thrombosis, transdermal oestrogen is widely regarded as the lowest-risk systemic oestrogen option and should be part of an informed, individualised conversation rather than dismissed outright.

As with all areas of menopause care, the goal is not to eliminate risk entirely - it is to make evidence-based decisions that balance risk, benefit and quality of life