HRT and breast cancer risk: the real numbers
HRT causes a small rise in breast cancer risk that grows with years of use. The rise is smaller with estrogen-only HRT, and low-dose vaginal estrogen shows no extra risk. For most women under 60 with symptoms, the benefits outweigh the risks.
Talk to your doctor before starting HRT if you have had breast cancer or have a strong family history. Whatever you take, go to breast screening when invited and see a GP about any new lump or change in your breasts.1
The short answer
All types of HRT taken by mouth or through the skin slightly raise breast cancer risk. The risk is higher with combined HRT than with estrogen-only HRT, and grows the longer you take it.2
Using HRT for less than a year adds little or no risk. The risk falls after stopping, but some extra risk can last more than 10 years.2
The numbers
The UK medicines regulator estimated the numbers below from a large 2019 analysis. They show breast cancers diagnosed between ages 50 and 69, for women who start HRT around menopause and take it for 5 years.2
| Group (per 1,000 women) | Breast cancers by age 69 |
|---|---|
| Never used HRT | About 63 |
| Estrogen-only HRT for 5 years | About 5 extra |
| Combined HRT, progestogen part of each month, for 5 years | About 14 extra |
| Combined HRT, progestogen every day, for 5 years | About 20 extra |
Taking HRT for 10 years roughly doubles these extra numbers.2 The NHS now gives a lower figure of around 5 extra cases per 1,000 women taking combined HRT for 5 years, and little or no increase with estrogen-only HRT.1 Estimates differ because studies and time periods differ.
What changes the risk
- Type: combined HRT carries more risk than estrogen-only HRT.2
- How long: risk rises with longer use. Less than a year adds little or no risk.2
- Route: tablets, patches and gels carry a similar breast risk, though patches and gels are safer for blood clots.1,2
- Type of progestogen: the 2019 analysis found similar risk whichever progestogen was used, including progesterone.2
- Vaginal estrogen: low doses used for vaginal symptoms showed no effect on breast cancer risk.2
Putting it in context
The NHS says that for women under 60 with menopause symptoms and no high risk of breast cancer or clots, the benefits of HRT are likely to outweigh the risks.1 HRT relieves hot flashes, night sweats, sleep problems and vaginal dryness, and helps prevent osteoporosis.1
In 2025, the US government removed the boxed warnings from HRT labels, saying they overstated the risks.3 Other everyday factors matter too. For example, drinking alcohol raises breast cancer risk.4
If you have had breast cancer or have a family history
If you have had breast cancer, you will usually be advised not to take HRT.1 Talk to your specialist about other options, such as non-hormonal prescription treatments.
With a strong family history, ask for a personal risk assessment before you decide.1
Ways to keep your risk low on HRT
- Review your HRT every year, and take it for as long as you need it.1
- If you have no womb, you can take estrogen-only HRT.1
- Go to every breast screening appointment, and check your breasts for changes.1
- Keep alcohol low.4
Common questions
Does estrogen-only HRT cause breast cancer?
It raises risk less than combined HRT. UK regulators estimated about 5 extra cases per 1,000 women over 5 years of use. The NHS says there is little or no increase.1,2
Is breast cancer risk lower with HRT patches or gel?
Not for the breasts. Breast risk was similar whether HRT was taken as tablets or through the skin. Patches and gels are safer for blood clots, though.1,2
Does the risk go away after stopping HRT?
It falls after you stop, but some extra risk can last for more than 10 years.2
Does vaginal estrogen increase breast cancer risk?
The 2019 analysis found no effect on breast cancer risk from low-dose vaginal estrogen.2 See vaginal estrogen.
Related
Sources
- Benefits and risks of hormone replacement therapy (HRT), NHS
- HRT: further information on the known increased risk of breast cancer with HRT and its persistence after stopping, MHRA Drug Safety Update (August 2019)
- HHS advances women's health, removes misleading FDA warnings on hormone replacement therapy, US Department of Health and Human Services
- Alcohol and breast cancer risk, Breast Cancer Research Foundation