Risks of HRT

There are possible risks of taking hormone replacement therapy (HRT). These risks include:

• breast cancer
• cardiovascular disease (conditions affecting the heart and blood vessels)
• a stroke
• a blood clot

Your doctor or nurse talks to you about the risks and how they might affect you.

The information leaflet that comes with your HRT might just talk about risks for people over the age of the natural menopause (about 50 years old). If you're younger and are given HRT after a hysterectomy or for early menopause, there might be more benefits to taking HRT than in those who are older. 

The benefits and risks of HRT explained here are taken from National Institute of Clinical Excellence (NICE) guidelines. 

Breast cancer

If you are under the age of 50 and take HRT, there is no extra risk of breast cancer. You still have the same risk of breast cancer as the rest of the population.

There is an increased risk for people over 50 who take combined HRT (oestrogen and progesterone taken together).

Research suggests that for every 1,000 people taking combined HRT for between 7 and 8 years, there are between 5 and 17 more cases of breast cancer than in those not taking HRT. 

The risk of breast cancer increases the longer you take HRT, and lowers when you stop HRT. 

The latest research shows that breast cancers found in people who take HRT are easier to treat. 

Cardiovascular disease and stroke

There is a slightly increased risk of cardiovascular disease and a stroke for women over 60 who take HRT. This is more likely if they started HRT late into the menopause and use combined HRT.

The risk can depend on the amount (dose) of HRT and how you take it. The risk is lower if the dose of HRT is smaller, or if you are use an HRT gel or patch.

Blood clot (deep vein thrombosis or DVT)

There is a risk of getting a blood clot if you take HRT. This depends on other things, such as if you smoke, your weight, your age and the way that you take HRT. It's thought that there is less risk if you use skin patches or a gel.

There is a slight increase in the risk of blood clots during the first year of treatment. 

The risk of a blood clot is much lower than if you take the contraceptive pill or are pregnant.