Hormone replacement therapy (HRT) is a treatment used to relieve symptoms of the menopause. It replaces female hormones that are at a lower level as you approach the menopause.
The menopause, sometimes referred to as the "change of life", is when a woman's ovaries stop producing an egg every 4 weeks. This means she will no longer have monthly periods or be able to have children naturally.
The menopause usually occurs when a woman is in her 50s (the average age is 51 in the UK), but some women experience the menopause in their 30s or 40s.
Read more about the menopause.
Oestrogen and progesterone (see below) are female hormones that play important roles in a woman’s body. Falling levels cause a range of physical and emotional symptoms, including hot flushes, mood swings and vaginal dryness.
The aim of HRT is to restore female hormone levels, which can bring relief to many women.
Oestrogen helps to release eggs from the ovaries. It also regulates a woman’s periods and helps her to conceive.
Oestrogen also plays a part in controlling other functions, including bone density, skin temperature and keeping the vagina moist. It is a reduction in oestrogen that causes most symptoms associated with the menopause, including:
Most symptoms will pass within 2 to 5 years, although vaginal dryness is likely to get worse if not treated. Stress incontinence may also persist and the risk of osteoporosis will increase with age.
The main role of progesterone is to prepare the womb for pregnancy. It also helps to protect the lining of the womb, known as the endometrium.
A decrease in the level of progesterone does not affect your body in the same way as falling levels of oestrogen. However, taking oestrogen as HRT on its own when you have a womb increases the risk of womb (uterus) cancer, sometimes called endometrial cancer.
A synthetic form of progesterone, called progestogen, is usually used in combination with oestrogen in HRT.
However, if you have had a hysterectomy (an operation to remove your womb), you do not need progesterone and can take oestrogen-only HRT.
Read more about the different types of HRT.
How systemic HRT is taken
Tablets, patches or implants are only needed if you have menopausal symptoms, such as hot flushes, and have weighed up the benefits and risks of treatment.
There are many different combinations of HRT, so deciding which type to use can be difficult. Your GP will be able to advise you.
There are several ways HRT can be taken, including:
- tablets – which can be taken by mouth
- a patch that you stick on your skin
- an implant – under local anaesthetic, small pellets of oestrogen are inserted under the skin of your tummy, buttock or thigh
- oestrogen gel – which is applied to the skin and absorbed
Local oestrogen for vaginal dryness
If you are only experiencing vaginal dryness, you will probably be recommended oestrogen preparations that can be applied directly to your vagina.
As the dose of oestrogen is so low, you do not require the protective effect of the progestogen. Local oestrogens do not carry the same risks associated with systemic combined HRT.
Local oestrogens can be in the form of:
- pessaries placed directly into the vagina
- a vaginal ring
- vaginal creams
When to stop taking HRT
Most women are able to stop taking HRT after their menopausal symptoms finish, which is usually two to five years after they start.
Gradually decreasing your HRT dose is usually recommended, rather than stopping suddenly. You may have a relapse of menopausal symptoms after you stop HRT, but these should pass within a few months.
If you have symptoms that persist for several months after you stop HRT, or if you have particularly severe symptoms, contact your GP because treatment may need to be restarted, usually at a lower dose.
After you have stopped HRT, you may need additional treatment for vaginal dryness and to prevent osteoporosis (brittle bones). Read about the best ways to prevent osteoporosis.
Creams and lubricants are available for vaginal dryness, as are local oestrogen preparations (see above).
Who can use HRT?
You can start HRT as soon as you begin to experience menopausal symptoms. However, HRT may not be suitable if you are pregnant or have:
If you have irregular periods, this will also need to be diagnosed before HRT is used.
Read more about who can use HRT.
If you are unable to have HRT, different medication may be prescribed to help control your menopausal symptoms.
Read more about alternatives to HRT.
Side effects of HRT
Hormones used in HRT can have associated side effects, including:
Read more about possible side effects of HRT and how to ease them.
Benefits and risks
Over the years, many studies examining the benefits and risks of HRT have been carried out.
The main benefit is that it is a very effective method of controlling menopausal symptoms, and it can make a significant difference to a woman’s quality of life and wellbeing.
HRT can also reduce a woman’s risk of developing osteoporosis and cancer of the colon and rectum. However, long-term use is rarely recommended, and bone density will decrease rapidly after HRT is stopped.
Combined HRT slightly increases the risk of developing breast cancer, womb cancer, ovarian cancer and stroke. Systemic HRT also increases your risks of deep vein thrombosis (DVT) and pulmonary embolism (blockage in the pulmonary artery). Other medicines are available to treat osteoporosis that do not carry the same level of associated risk.
Most experts agree that if HRT is used on a short-term basis (no more than five years), the benefits outweigh the risks.
If HRT is taken for longer, particularly for more than 10 years, you should discuss your individual risks with your GP and review them on an annual basis.
Read more about the risks of HRT.