Hormone replacement therapy (HRT)

What is hormone replacement therapy?

All types of HRT contain an oestrogen hormone. If you take HRT it replaces the oestrogen that your ovaries no longer make after the menopause. Some types contain a progestogen hormone as well.

However, if you just take oestrogen then the lining of your womb (uterus) builds up, increasing the risk of developing cancer of the womb (endometrial cancer). Therefore, the oestrogen in HRT is usually combined with a progestogen hormone.

The risk of cancer of your womb is completely reduced by adding in the progestogen. In many HRT products, the oestrogen and progestogen are combined in the same patch or tablet; however, they can also be taken separately. If you have had a hysterectomy or have a contraceptive intrauterine system fitted (Mirena®), you do not need a progestogen.

An option to ease symptoms just in the vaginal area is to use a cream, vaginal tablet (pessary), or vaginal ring that contains oestrogen. See the separate leaflet called Vaginal dryness (Atrophic vaginitis).

Types of HRT

Different women prefer different methods of taking HRT. The options include: patches, tablets and topical gel or spray (applied to the skin) . Patches and gel are increasingly popular forms of HRT, and many women find them convenient to use.

Unlike tablets, patches and gel do not increase your risk of blood clots. Your doctor or practice nurse can give you information about the pros and cons of the different types of HRT.

Cyclical combined HRT

If you start HRT when you are still having periods, or have just finished periods, you will normally be advised to use 'cyclical combined HRT' (also known as 'sequential HRT'):

• Monthly cyclical HRT - you take oestrogen every day but progestogen is added in for 14 days of each 28-day treatment cycle. This causes a regular bleed every 28 days, similar to a light period. (They are not 'true' periods, as HRT does not cause ovulation or restore fertility. The progestogen causes the lining of your womb to build up. This is then shed as a 'withdrawal' bleed every 28 days when the progestogen part is stopped.) Monthly cyclical HRT is normally advised for women who have menopausal symptoms but are still having regular periods.

You may switch to a continuous combined HRT (see below) if:

• You have been taking cyclical combined HRT for at least one year; or

• It has been at least one year since your last menstrual period.

Continuous combined HRT

If your periods have stopped for a year or more, you are considered to be postmenopausal. If this is the case, you will normally be advised to take a 'continuous combined HRT preparation'.

This means that you take both an oestrogen and a progestogen every day. You may have some irregular bleeding in the first 3-6 months after starting this form of HRT. You should see your doctor if this bleeding is very heavy, or if it continues for more than six months after starting HRT, or if you suddenly develop bleeding after some months with no bleeding.

Oestrogen HRT

If you have had a hysterectomy, you will usually need to take HRT that contains oestrogen only. The progestogen is only added in to other types of HRT so that the lining of the womb does not build up and increase your risk of developing cancer of the womb. So, if your womb has been totally removed, progestogen is not needed. However, if the hysterectomy was for endometriosis or was sub-total then both hormones might be needed – talk to your GP to check if needed.

If you have a Mirena® intrauterine system (IUS) for contraception, you will only need to take HRT that contains oestrogen. This is because an IUS (eg, Mirena®) already contains enough progestogen to stop the lining of your womb from building up. See the separate leaflet called Intrauterine System (IUS) for more information. Note that there are several types of IUS available which can be used for contraception and heavy periods but only the Mirena® is used for menopause hormone replacement.

Vaginal oestrogen cream and other topical preparations

For vaginal dryness (atrophic vaginitis) or bladder symptoms, you may choose to try a vaginal oestrogen cream or a pessary to help your symptoms.

This alone may be enough to relieve symptoms in some women who would prefer this option or who cannot take other forms of HRT for some reason.

Vaginal oestrogen creams can also be used in addition to other forms of HRT, if required to improve symptoms. They are now available to buy from pharmacies.

Testosterone

Testosterone gel is sometimes prescribed to menopausal women who complain of low sexual desire if HRT alone is not effective. This is not a licensed usage, meaning this medication is not formally approved or regulated for this use. Testosterone for menopausal women is usually only prescribed on the advice of a specialist or by a GP with a particular interest in management of the menopause.

What are the benefits of HRT?

HRT is a safe and effective treatment option for most healthy women with symptoms, who are going through the menopause at the average age in the UK (about 51 years). The risks and benefits of HRT will vary according to your age and any other health problems you may have. Your doctor will be able to discuss any potential risks of HRT with you in detail.

Menopausal symptoms usually improve

This can make a big difference to quality of life in some women:

• HRT works to stop hot flushes (also known as 'hot flashes') and night sweats.

• HRT will reverse many of the changes around the vagina and vulva. This means that HRT can:

  • Improve symptoms of vaginal dryness.

  • Improve discomfort during sexual intercourse as a result of this vaginal dryness.

  • Help to reduce recurrent urine infections.

  • Improve any increased frequency of passing urine.

• There is some evidence that HRT itself can improve your mood and your sleep.

• HRT may also help to reduce joint aches and pains and it may improve muscle strength.

• HRT improves sexual function and libido in many women.

• Many women notice that the texture of their hair and skin improves when taking HRT.

Reduced risk of 'thinning' of the bones (osteoporosis)

Women who take HRT have a reduced risk of osteoporosis and their risk of having fractures due to osteoporosis is also reduced. Prevention of osteoporosis continues the longer you take HRT.

How long does HRT take to work?

HRT works within a few weeks to improve hot flushes and night sweats. It takes 1-3 months to reverse many of the changes to the vagina and vulva but it may take up to one year to notice the full benefit here.

Most doctors will recommend a trial of HRT for three months to see if it helps. If it does not they may recommend a change of dose or changing to a different type of HRT.

Can you take HRT for the rest of your life?

There is no limit on how long you can take HRT, although some risks increase the longer you take it for (eg, breast cancer). Most women stop taking it after a few years, when their menopausal symptoms resolve.

It is recommended that HRT should be reduced gradually rather than stopping suddenly. This may limit recurrence of symptoms in the short term but makes no difference in the long term.

What are the risks of HRT?

Side-effects with HRT are uncommon. They may include the following:

• In the first few weeks some women develop a slight feeling of sickness (nausea), mild headache, some breast discomfort or leg cramps. These tend to go within a few months if you continue to use HRT.

• HRT skin patches and gels occasionally cause irritation of the skin.

• Some women have migraine headaches when they take HRT. This is usually reduced by using patches or gel rather than taking tablets.

Most people do not experience side-effects with HRT use. However, a change to a different brand or type of HRT may help if side-effects occur. Various oestrogens and progestogens are used in the different brands. If you have a side-effect with one brand, it may not occur with a different one. Changing the delivery method of HRT (for example, from a tablet to a patch) may also help if you have side-effects.

There has been a lot of media attention to the risks of taking HRT. HRT can increase your risk of developing certain problems but this increase in risk is very small in most cases. These include:

Clots in the veins (venous thromboembolism)

This is a blood clot that can cause a deep vein thrombosis (DVT). In some cases the clot may travel to your lung and cause a pulmonary embolism (PE). Together, DVT and PE are known as venous thromboembolism.

Women who take combined HRT as tablets have an increased risk of developing a clot. You are more likely to develop a clot if you have other risk factors for a clot. These include being obese, having a clot in the past and being a smoker.

This increased risk of clots is not present for women who use patches or gel at standard doses rather than HRT tablets. Note: you should see a doctor urgently if you develop a red, swollen or painful leg, or have shortness of breath and/or sharp pains in your chest.

Breast cancer

The most recent research suggests that the risk of breast cancer is increased for all women taking HRT. However, this risk is much lower than previously thought.

The increased risk depends on the type of HRT you take and how long you take it for. For example, for women starting HRT at age 50 and taking it for five years, an extra one woman will be diagnosed with breast cancer between age 50 and 69 years for every:

• 50 women taking continuous combined HRT.

• 70 women taking combined monthly cyclical HRT.

• 200 women taking oestrogen-only HRT.

Women who have taken HRT are at some increased risk of developing breast cancer for at least 10 years after stopping. The risk is also increased in women in their 40s taking HRT, but in real terms this risk is lower because fewer women develop breast cancer at this age. Current guidance is to offer HRT to all women going through early menopause (before age 45) because HRT helps to protect against osteoporosis in this group.

Of note, oestrogen‑only HRT (ie without any progestogen) causes little or no change in the risk of breast cancer.

Cancer of the womb

There is an increased risk of womb (uterine) cancer due to the oestrogen part of HRT. However, by taking combined HRT containing oestrogen and progestogen, this risk reduces completely.

You should always see your doctor if you have any abnormal vaginal bleeding which develops after starting HRT. For example, heavy bleeding, irregular bleeding, or bleeding after having sex.

Heart disease

There is no increased risk of heart disease when HRT is started in women under the age of 60. There may be a small increased risk of heart disease when HRT is started in older women (over 60) or those who already have some form of heart disease.

Stroke

HRT tablets (but not patches or gels) slightly increase the risk of stroke. However, it is important to remember that the risk of stroke in women under 60 is very low.

Does HRT cause weight gain?

There is no evidence that HRT causes weight gain. Many women notice some weight gain during the menopause but this happens whether they take HRT or not.