Hormone Replacement Therapy (HRT): What You Need to Know About the Risks
What is HRT?
- HRT replaces hormones (mainly oestrogen, sometimes combined with progestogen) that fall after the menopause.
- It helps with hot flushes, sweats, mood changes, sleep problems, and bone thinning.
- Oestrogen replacement given alone to women with a uterus can increase endometrial cancer risk. A progestogen is therefore given to reduce this risk and that it is important if you are prescribed both that you take both.
Benefits of HRT
• Eases menopausal symptoms
• Protects bones and reduces fracture risk
• May improve sleep, mood, and quality of life
• Can improve vaginal and bladder symptoms
Possible Risks of HRT
Breast Cancer
• There is a slightly higher risk of breast cancer, especially with combined HRT (oestrogen + progestogen). The risk probably increases slightly after of 5 years’ use of combined HRT. Over the age of 50 – there are an additional 3-4 cases per 1,000 women. More information on breast cancer risk can be found here.
• Studies suggest that suggest that micronized progesterone such as utrogestan are likely to be associated with a lower risk of invasive breast cancer compared with progestogens such as medroxyprogesterone.
• Oestrogen alone HRT has a much lower risk of breast cancer.
• Risk increases with longer use but reduces after stopping.
• Mortality ( death as a result of breast cancer) is not increased.
Blood Clots
• There is a small increase in risk of blood clots with HRT tablets. On average women over the age of 50 who are not on HRT have a the following risk of developing a blood clot – 1.7 per 1,000. The risk of blood clots increases 2-4 times in the first year of taking HRT.
• The risk of developing a blood clot is greatest in the first 12 months of taking HRT.
• There is no increase in the risk of blood clots if you use oestrogen that is absorbed through the skin and there is probably no increased risk if you use oestrogen absorbed through the skin along with micronized progesterone e.g. utrogestan.
Stroke
• The risk of stroke is age related and overall, the risk is low in women under the age of 60.
• Oral oestrogen is likely to be associated with a small increase in the risk of stroke. This effect is likely to be dose related and the lowest effective dose should therefore be
prescribed.
• Transdermal oestrogen is unlikely to increase the risk of stroke above the woman’s own baseline risk.
• Risk is very low in younger women.
Heart Disease
• Starting HRT before age 60 does not increase risk.
• Starting at an older age may carry more risk.
Ovarian Cancer
• Tiny increase in risk, which disappears after stopping.
How to Reduce Risks
• Use the lowest effective dose for the shortest time you need.
• Go to routine breast screening appointments when offered.
• Keep a healthy, active lifestyle.
When HRT is not suitable
HRT is not recommended if you have or have had:
• Breast or ovarian cancer
• Blood clots or stroke
• Uncontrolled high blood pressure
• Severe liver disease
Weight Loss Medication and HRT
If you are taking HRT alongside a weight loss medication or a medication that affects the absorption of food please speak to a GP. Weight loss medication such as Mounjaro reduce the absorption of HRT tablets and as a result can lead to a higher risk of endometrial cancer.
When to seek medical advice whilst taking HRT
- If you develop a breast lump or have any concerns that you may be at high risk of breast cancer
- If you have a period /develop vaginal bleeding after your periods have stopped
- If you have had a stroke or a heart attack
- If your blood pressure is high
- If you have started taking weight loss medication or medication affecting the absorption of drugs
- BMS & WHC’s 2020 recommendations on hormone replacement therapy in menopausal women. https://thebms.org.uk/wp-content/uploads/2023/10/02-BMS-ConsensusStatement-BMS-WHC-2020-Recommendations-on-HRT-in-menopausal-women-SEPT2023-A.pdf
