Hormone replacement therapy (HRT)

16 min read

What is HRT?

Hormone replacement therapy (HRT) is a treatment used to relieve symptoms of menopause. It replaces the female hormones no longer produced after 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 that she will no longer have monthly

or be able to have children. The menopause usually occurs when a woman is in her 50s (the average age is 52).

Read more about the


Oestrogen and progesterone (see below) are female hormones that play important roles in a woman’s body. When levels fall, it causes a range of physical and emotional symptoms, including hot flushes, mood swings and vaginal dryness.

HRT helps 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 menopause, including:

  • hot flushes
  • night sweats
  • vaginal dryness
  • loss of sex drive (libido)
  • stress incontinence: leaking urine when you cough or sneeze
  • thinning of the bones: this can lead to brittle bones (osteoporosis)

Read more about

unusual menopause symptoms to look out for

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

. It also helps to protect the lining of the womb, which is 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, but it does increase your risk of developing womb cancer (endometrial cancer).

Progesterone is therefore usually used in combination with oestrogen in HRT. However, if you have had a

(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 HRT is taken

There are several ways HRT can be taken, including:

  • as a cream or gel, which can be applied to the skin or directly into the vagina if you are experiencing vaginal dryness
  • tablets, which can be taken by mouth or placed directly into your vagina to treat dryness
  • 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

If you are only experiencing vaginal dryness, a type of HRT that can be applied directly to your vagina will probably be recommended.

Tablets, patches or implants are only needed if you have other menopausal symptoms, such as hot flushes.

There are many different combinations of HRT, so deciding which type to use can be difficult. Your doctor will be able to advise.

Read more about

how HRT is taken

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 endometrial cancer
  • a history of
    blood clots
  • a history of heart disease or
  • untreated
    high blood pressure
    (your blood pressure will need to be controlled before you can start HRT)
  • liver disease

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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:

  • fluid retention
  • bloating
  • breast tenderness or swelling
  • headaches
  • indigestion
  • depression

Read more about possible

side effects of HRT and how to alleviate them

Benefits and risks

Over the years, many studies have been carried out looking at the effects of HRT, but recent evidence says the risks are small and are usually outweighed by the benefits.

These benefit are that HRT is a very effective method of controlling menopause symptoms. 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 fall rapidly after HRT is stopped.

HRT slightly increases the risk of developing breast cancer, endometrial cancer, ovarian cancer and stroke, and other medicines are available to treat osteoporosis that do not carry the same level of associated risk.

Most experts agree if HRT is used on a short-term basis (no more than 5 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 doctor and review them on an annual basis.

Read more about the

risks of HRT

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 try the treatment plan you have been prescribed for at least three months.

If side effects continue after this time, see your doctor so your treatment plan can be reviewed.

If side effects persist, your doctor 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:

In some cases, small lifestyle changes can help to relieve side effects. For example:

  • taking your oestrogen dose with food may help to reduce nausea and indigestion
  • eating a low-fat, high-carbohydrate diet may reduce breast tenderness
  • regular exercise and stretching can help to reduce leg cramps

Side effects of progestogen

Side effects associated with progestogen include:

Alternatives to HRT

If you are unable or decide not to take hormone replacement therapy (HRT), alternative approaches and treatments are available that may help control your menopausal symptoms.

Lifestyle changes

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.
  • 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,


Tibolone is a synthetic (man-made) hormone that can be used as an alternative to HRT. It contains a combination of oestrogen and progestogen, so you only need 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, it is likely you will not be able to take tibolone.


The following antidepressants have proven effective in treating hot flushes in some menopausal women:

Side effects of these antidepressants include:

  • nausea
  • blurred vision
  • diarrhoea or constipation
  • dizziness
  • dry mouth
  • loss of appetite
  • sweating
  • feeling agitated
  • insomnia
    (difficulty getting or staying asleep)

SSRIs have also been associated with a

loss of libido
(sex drive).

Any side effects will usually improve over time, but visit your doctor if they do not.

You may need to have regular blood tests or blood pressure checks when taking antidepressants, particularly if you also take the anti-clotting medicine,

, or have
high blood pressure


Clonidine is a medicine originally designed to treat high blood pressure, but research shows it may reduce hot flushes in some menopausal women.

Side effects of clonidine include:

  • low blood pressure
  • dizziness
  • drowsiness
  • dry mouth
  • fluid retention

Using clonidine is not recommended if you have

or insomnia because it could make these conditions worse.


Gabapentin is a medicine originally designed to treat pain and epileptic seizures. However, as with clonidine, gabapentin has been shown to help ease hot flushes in some menopausal women.

Side effects of gabapentin can include:


In some menopausal women, a medicine called pregabalin has been shown to reduce the frequency and severity of hot flushes.

Side effects of pregabalin can include:

  • dizziness
  • weight gain
  • sleepiness
  • co-ordination problems
  • difficulty concentrating
  • blurred or double vision

These side effects are usually mild.

Although the chances of being pregnant as you approach the menopause is small, this will vary depending on how long ago you had your last period.

Pregabalin and Gabapentin are not recommended if you are pregnant unless your doctor feels that the benefits clearly outweigh the risks. There is evidence that pregabalin may cause harm to the baby and with gabapentin there is not enough information to say that it is safe. Therefore, it is recommended that women who take pregabalin take effective contraception to stop them getting pregnant whilst taking it. If you are planning to become pregnant or find out that you are pregnant whilst taking this medication/these medications, speak to your doctor and midwife as soon as possible.

Complementary therapies

Some products are sold in health shops for treating menopausal symptoms. These herbal remedies include ginseng, black cohosh, red clover and evening primrose oil.

These products are often marketed as "natural", but this does not necessarily mean they are safe to use. Concerns exist over 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 are effective. Therefore, always consult your doctor before using a complementary therapy to treat menopausal symptoms.

Disadvantages 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 which 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, just 1%. So using HRT for five years would only increase the average risk from 1% to 1.6%.

Breast cancer

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 the 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.

Read more about HRT and breast cancer risk on the Cancer Research UK website.

Due to the associated risk of breast cancer, if you are taking HRT it is important you attend all your breast-screening appointments.

Ovarian cancer

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.

Read more about

HRT and ovarian cancer risk
on the Cancer Research UK website.

Endometrial cancer

If you take progestogen as directed, there is no increased risk of developing

endometrial cancer
(cancer of the womb).

It is very important you take progestogen as directed because only taking oestrogen will significantly increase your risk of developing endometrial cancer.

Stroke and heart attacks

Preliminary results of a recent American study have suggested a small increased risk of

heart disease
for women taking HRT.

However, British researchers currently carrying out a 10-year study, say at present evidence is inconclusive.

Dosage of HRT

There are several ways hormone replacement therapy (HRT) can be taken.

HRT can be taken as:

  • a cream or gel: applied to the skin or directly into the vagina if you are experiencing vaginal dryness
  • tablets: taken by mouth or placed directly into your vagina to treat dryness
  • a patch you stick on your skin
  • an implant: small pellets of oestrogen are placed under the skin of your tummy, buttock or thigh

If you are only experiencing vaginal dryness, you may be advised to use a form of HRT that can be applied directly to your vagina.

Tablets, patches and implants are only usually required if you have other

menopausal symptoms
, such as hot flushes.

There are different combinations of HRT which may make it difficult for you to decide which one is best for you. Your doctor will be able to advise you.

The hormones used in HRT will usually be prescribed at the lowest possible dose to control your symptoms. It may take a while to establish an effective dose for your symptoms. Tell your doctor if you feel your current dose is not working.

When to stop taking HRT

Most women are able to stop taking HRT after their menopausal symptoms finish. This 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 doctor 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

(brittle bones). Creams and lubricants are available for vaginal dryness, and medicines called bisphosphonates have proved effective in treating osteoporosis.

How HRT works

Hormone replacement therapy (HRT) replaces two female hormones that a woman’s body is no longer producing due to

. These hormones are:

  • oestrogen: the oestrogen used in HRT is taken from plants or from the urine of pregnant horses
  • progesterone: HRT uses a synthetic version of progesterone called progestogen because it is easier for the body to absorb

While there are more than 60 different preparations of HRT, the three main types are discussed below.

Oestrogen-only HRT

Oestrogen-only HRT is usually recommended for women who have had their womb and ovaries removed during a

. There is no need to take progestogen because there is no risk of
endometrial cancer
(cancer of the lining of the womb).

Cyclical HRT

Cyclical HRT, also known as sequential HRT, is often recommended for women who have menopausal symptoms but still have their


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 14 days
  • three-monthly HRT: where you take oestrogen every day and progestogen for 14 days, every 13 weeks

Monthly HRT is usually recommended for women having regular periods. You will continue to have monthly periods until the menopause causes them to stop.

Three-monthly HRT is usually recommended for women experiencing

irregular 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.

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

is 52. However, some women have the menopause when they are in their forties or sixties. There is no way of predicting exactly when the menopause will occur.

Some women have

menopausal symptoms
, such as hot flushes and vaginal dryness, before menopause actually starts. 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 number. This means you may experience menopausal symptoms even when you are still having


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 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) or cervical cancer.

When HRT is not suitable

HRT may not be suitable if you:

In these circumstances, a different type of medication may be prescribed to help control your menopausal symptoms.

Read more about the

alternatives to HRT

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.