Hormone replacement therapy (HRT)

Hormone replacement therapy (HRT)


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

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

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 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.

Contraception, pregnancy and HRT

Oestrogen used in HRT is different from oestrogen used in the contraceptive 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 IUS (intrauterine system), 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.

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 having periods.

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:

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

Read more about the alternatives to HRT.

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 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. Read more about treating sleep problems
  • 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 diseasestroke 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:

  • venlafaxine hydrochloride
  • citalopram

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.

Complementary therapies

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 as yogaaromatherapy (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:

  • fluid retention
  • bloating
  • breast tenderness or swelling
  • nausea
  • leg cramps
  • headaches 
  • indigestion 

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:

Weight gain

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.

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%.

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 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, it is important to attend all your breast-screening appointments if you are taking HRT.

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.

Womb cancer

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 or deep vein thrombosis (DVT)

Speak to your GP if you are taking HRT and are worried about the risk of stroke or heart disease.

“The night sweats really got me”

Barbara Hunt, a retired civil servant from Canterbury, Kent, has had a rollercoaster ride with the menopause and HRT.

“I was 51 when I had my first hot flush. My periods had been erratic for six months, so I realised I was approaching the menopause. Then the flushes started with a vengeance.

“My GP immediately suggested HRT. This was when it was being hailed as the wonder drug. I started off with patches. I still had periods, but at least the flushes went away.

“After four years, I heard about its possible side effects and decided to stop taking it. The flushes returned and I got night sweats, too. Heat would suddenly engulf me, then disappear just as quickly. The night sweats were really hard. I was waking up every half-hour and got so little sleep that going back on HRT seemed my only option.

“I started taking it again. To my relief, the flushes and sweats are a thing of the past. I’m now trying to wean myself off the patches by cutting a third off them each time. Having gone on HRT, it seems to be such a tough job to get off it. I sometimes wonder whether, if I’d never taken it, the flushes might be over by now.”