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 four 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.
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, allowing the body to function normally again.
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:
loss of libido (sex drive)
stress incontinence (leaking urine when you cough or sneeze)
bone thinning – which can lead to osteoporosis and fractures
Most symptoms will pass within two to five 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.
Progesterone is therefore 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.
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 isapplied 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
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).
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:
a history of breast cancer, ovarian cancer or womb cancer
a history of blood clots
a history of heart disease or stroke
untreated high blood pressure – your blood pressure will need to be controlled before you can start HRT
If you have irregular periods, this will also need to be diagnosed before HRT is used.
If you are unable to have HRT, different medication may be prescribed to help control your menopausal symptoms.
Side effects of HRT
Hormones used in HRT can have associated side effects, including:
breast tenderness or swelling
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.
Types of HRT
Hormone replacement therapy (HRT) replaces female hormones that a woman’s body is no longer producing, due to the menopause.
These hormones are:
oestrogen – which is taken from either plants or the urine of pregnant horses
progesterone – HRT uses a synthetic version of progesterone called progestogen, which is easier for the body to absorb
Choosing the right HRT for you
Finding the right type of HRT can be tricky.
A low dose of HRT hormones is usually recommended to begin with. It is best to start with the lowest effective dose, to minimise side effects. If necessary, you can increase your dose at a later stage.
Persevere with HRT and wait a few months to see if it works well for you. If not, you can try a different type or increase the dose. Talk to your GP about any problems you have with HRT.
While there are more than 50 different preparations of HRT, the three main types are discussed below.
Oestrogen-only HRT is usually recommended for women who have had their womb removed during a hysterectomy. There is no need to take progestogen because there is no risk of womb (uterus) cancer, sometimes called endometrial cancer.
Cyclical HRT, also known as sequential HRT, is often recommended for women who have menopausal symptoms but still have their periods.
There are two types of cyclical HRT:
monthly HRT – where you take oestrogen every day and progestogen at the end of your menstrual cycle for 12-14 days
three-monthly HRT – where you take oestrogen every day and progestogen for 12-14 days, every 13 weeks
Monthly HRT is usually recommended for women having regular periods.
Three-monthly HRT is usually recommended for women experiencingirregular periods. You should have a period every three months.
It is useful to maintain regular periods so you know when your periods naturally stop and when you are likely to progress to the last stage of the menopause.
In some cases, a woman using cyclical HRT may continue having periods after the menopause (when she is post-menopausal).
Continuous combined HRT
Continuous combined HRT is usually recommended for women who are post-menopausal. A woman is usually said to be post-menopausal if she has not had a period for a year.
As the name suggests, continuous HRT involves taking oestrogen and progestogen every day without a break.
Contraception, pregnancy and HRT
Oestrogen used in HRT is different from oestrogen used in thecontraceptive pill, and is not as powerful.
This means it's possible to become pregnant if you are taking HRT to control menopausal symptoms. In some cases, a woman can be fertile for up to two years after her last period if she is under 50, or for a year if she is over 50.
If you don't want to get pregnant, you can use a non-hormonal method of contraception, such as a condom or diaphragm.
An alternative is the intrauterine device (IUD), which is also licensed for heavy periods and as the progestogen part of HRT. You will need to add oestrogen as either a tablet, gel or patch.
An IUD needs to be inserted by a trained clinician and will give protection for 5-10 years, depending on the type.
Who can use HRT
You can begin hormone replacement therapy (HRT) as soon as you start experiencing menopausal symptoms.
The average age for women to experience the menopause in the UK is 51. However, some women have the menopause when they are in their 30s, 40s or 60s. There is no way of predicting exactly when the menopause will happen.
Some women have menopausal symptoms, such as hot flushes and vaginal dryness, in the three to four years before the menopause. This is known as the peri-menopause.
The peri-menopause occurs because levels of the female sex hormones, oestrogen and progesterone, fall when the number of remaining eggs drops below a certain level. This means you may experience menopausal symptoms even when you are still havingperiods.
In most cases, HRT can be used without taking a test to confirm you are starting the menopause. A test for the menopause is usually only necessary if you are under 40 years old or have unusual bleeding patterns during your period.
Testing can help rule out other conditions that may cause similar symptoms, such as having an overactive thyroid gland (hyperthyroidism). You should have regular smear tests for cervical cancer.
When HRT is not suitable
HRT may not be suitable if you:
have a history of breast cancer, ovarian cancer or womb (uterus) cancer
have a history of blood clots
have a history of heart disease or stroke
have untreated high blood pressure – your blood pressure will need to be controlled before you can start HRT
have liver disease
In these circumstances, a different type of medication may be prescribed to help control your menopausal symptoms.
Alternatives to HRT
If you are unable to or decide not to undertake hormone replacement therapy (HRT), alternative approaches and treatments are available that may help control your menopausalsymptoms.
Making changes to your lifestyle may help ease your menopausal symptoms. For example, you should:
Take regular exercise
– regular activity has been shown to reduce symptoms of hot flushes and improve sleep; it is also a good way of boosting your mood if you feel anxious, irritable or depressed.
Stay cool at night – wearing loose clothes and sleeping in a cool, well-ventilated room may help relieve hot flushes and night sweats.
Cut down on caffeine, alcohol and spicy food – as they have all been known to trigger hot flushes.
Try to reduce your stress levels
– to improve mood swings, make sure you get plenty of rest, as well as getting regular exercise. Activities such as yoga and tai chi can help you relax.
Give up smoking
– if you smoke, giving up will help reduce hot flushes and your risk of developing serious health conditions, such as heart disease, stroke and cancer.
Tibolone is a man-made (synthetic) hormone that can be used in post-menopausal women who have a womb. It contains a combination of oestrogen and progestogen, so you only need to take one tablet.
If you are unable to take HRT for medical reasons – for example, if you have a history of breast cancer or heart disease – you will probably not be able to take tibolone.
Tiboline is not suitable if you are experiencing symptoms of the menopause before it actually starts (known as the peri-menopause) or within a year of your last period.
Although antidepressant medications aren't licensed for treating hot flushes, there are several that may be effective, including:
Potential side effects of these antidepressants include nausea, dizziness, dry mouth, anxiety and sleeping problems.
Certain antidepressants have also been associated with a loss of libido (sex drive).
Any side effects will usually improve over time, but you should visit your GP if they don't.
You may need to have regular blood tests or blood pressure checks when taking antidepressants, particularly if you also take the anti-clotting medicine warfarin or have high blood pressure (hypertension).
Clonidine is a medicine originally designed to treat high blood pressure, but research shows it may reduce hot flushes and night sweats in some menopausal women.
Clonidine can cause unpleasant side effects, including dry mouth, drowsiness, depression, constipation and fluid retention.
You will need to take it for a trial period of two to four weeks, to test its effectiveness. If your symptoms don't improve during this time, or if you experience any side effects, the treatment should be stopped and you should go back to your GP.
Some products are sold in health shops for treating menopausal symptoms. These herbal remedies include evening primrose oil, black cohosh, angelica and ginseng.
These products are often marketed as "natural", but this does not necessarily mean they are safe to use. There are concerns about the quality of "natural products", and some may interact with other treatments and cause harmful side effects. There is also very little evidence to show that these remedies actually work.
Some women have reported that relaxation therapies – such asyoga, aromatherapy (PDF, 451kb) and reflexology (PDF, 272kb) – reduce their menopausal symptoms, but there's no scientific evidence to show that they're completely effective.
Ask your GP or pharmacist for advice if you're thinking about using a complementary therapy.
Side effects of HRT
Both hormones used in hormone replacement therapy (HRT), oestrogen and progestogen, have side effects.
Side effects usually improve over time, so it's best to try the treatment plan you have been prescribed for at least three months.
If side effects continue after this time, see your GP so your treatment plan can be reviewed.
If side effects persist, your GP may recommend:
switching to a different way of taking HRT – for example, changing from a tablet to a patch, or vice versa
changing the type of HRT you are taking – for example, a different form of oestrogen or progestogen
changing the dose of your HRT
Side effects of oestrogen
Side effects associated with oestrogen include:
breast tenderness or swelling
In some cases, small lifestyle changes can help to relieve side effects. These include:
taking your oestrogen dose with food, which may help to reduce nausea and indigestion
eating a low-fat, high-carbohydrate diet, which may reduce breast tenderness
regular exercise and stretching, which can help to reduce leg cramps
Side effects of progestogen
Side effects associated with progestogen include:
Many women believe taking HRT will make them put on weight, but there is no evidence to support this claim.
You may gain some weight during the menopause, but this often happens regardless of whether you take HRT or not.
Exercising regularly and eating a healthy diet should enable you to lose any unwanted weight.
Reporting side effects
The Yellow Card Scheme allows you to report suspected side effects from any type of medicine you are taking.
It is run by a medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA).
Understanding the risks of HRT
When deciding whether to have hormone replacement therapy (HRT), it is important to understand the risks and put them into perspective.
Many medical studies on HRT have been published over the past 10 years that have received a great deal of negative publicity. As a result, many women have been reluctant to use HRT.
However, it could be argued that the data within the studies was misleading. For example, if you read an article that says using combined HRT for five years increases your risk of developing breast cancer by 60%, you may be alarmed.
While this is statistically true, the average risk of developing breast cancer without other contributory risk factors (your annual baseline risk) is very small, at just 1%. This means that using HRT for five years would only increase the average risk from 1% to 1.6%.
Cancer Research UK summarises the breast cancer risk associated with HRT as follows:
Research has shown that taking HRT does increase breast cancer risk.
Combined HRT increases breast cancer risk more than oestrogen-only HRT.
Women taking combined HRT have double the breast cancer risk of women who do not take HRT.
The longer you take HRT, the more your breast cancer risk increases.
Your risk appears to return to normal within five years of stopping taking HRT.
Due to the associated risk of breast cancer, it is important to attend all your breast-screening appointments if you are taking HRT.
Cancer Research UK summarises the ovarian cancer risk associated with HRT as follows:
Research has shown that taking HRT slightly increases the risk of developing ovarian cancer.
The longer HRT is taken, the more the risk increases.
When HRT is stopped, risk returns to normal over the course of a few years.
If you take progestogen as directed, there is no increased risk of developing womb (uterus) cancer, which is sometimes referred to as endometrial cancer.
It is very important you take progestogen as directed, because only taking oestrogen will significantly increase your risk of developing womb cancer.
Combined HRT does not increase the risk of womb cancer.
Stroke and heart attacks
The latest analysis from Women's Health Concern regarding the risk of heart disease and stroke for women taking HRT states that:
the risk of stroke is increased in women who smoke and are overweight
women starting HRT and aged below 60 are not at an increased risk of stroke
HRT is not recommended for women with a history of stroke ordeep vein thrombosis (DVT)
Speak to your GP if you are taking HRT and are worried about the risk of stroke or heart disease.