Hormone Replacement Therapy HRT

Authored by , Reviewed by Dr Sarah Jarvis MBE | Last edited | Meets Patient’s editorial guidelines

Many women experience menopausal symptoms that affect their quality of life. Hormone replacement therapy (HRT) is the most effective form of treatment.

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. This increases your risk of developing cancer of the womb. 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 tablet; however, they can also be taken separately. If you have had a hysterectomy or have a contraceptive intrauterine system fitted, 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).

Different women prefer different methods of taking HRT. For example, some women prefer to wear a patch rather than taking tablets. Your doctor or practice nurse can give you information about the pros and cons of the different types of HRT.

If you start HRT when you are still having periods, or have just finished periods. You will normally be advised to use a 'cyclical combined HRT' preparation:

  • 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 (uterus) 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.

If you start HRT a year or more after your periods have stopped. 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 continues for more than six months after starting HRT, or if you suddenly develop bleeding after some months with no bleeding.

If you have had a hysterectomy. You will only need to take HRT that contains oestrogen. 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.

If you have an intrauterine system (IUS) for contraception. You will only need to take HRT that contains oestrogen. This is because an IUS (sometimes called a hormone coil) 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.

If you mainly have genital symptoms - for example, vaginal dryness or bladder symptoms. For vaginal dryness (atrophic vaginitis) you may choose to try some 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. However, in around one in ten women, this treatment is not enough to improve symptoms and HRT is needed to be taken as well.

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HRT is a safe and effective treatment 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 to you in detail. 

Menopausal symptoms usually ease

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

  • HRT works to stop hot flushes and night sweats within a few weeks.
  • HRT will reverse many of the changes around the vagina and vulva usually within 1-3 months. However, it can take up to a year of treatment in some cases.
  • 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 improves your mood and your sleep.
  • HRT may also help to improve joint aches and pains.
  • HRT improves symptoms of vaginal dryness and improves sexual function 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. This risk reduces further the longer you take HRT.

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

  • In the first few weeks some women may develop a slight feeling of sickness (nausea), some breast discomfort or leg cramps. These tend to go within a few months if you continue to use HRT.
  • HRT skin patches may occasionally cause irritation of the skin.
  • Some women have more headaches or migraines when they take HRT. This is usually reduced by using patches or gel rather than taking tablets.

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 risk of clot is not present for women who use patches or gel at standard doses rather than tablets of HRT. 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.

Editor's note

Dr Sarah Jarvis, September 2019

HRT and the risk of breast cancer

In 2003, a study suggested an increased risk of breast cancer in women taking combined (oestrogen and progestogen) HRT. Since then, other studies have suggested that the risk might be lower than first thought, with some studies even suggesting there was no increased risk.

However,  a new review of studies on over 100,000 women suggests that the risk of breast cancer is increased for all women taking HRT,

According to this review, the increased risk depends on the type of HRT you take and how long you take it for. According to their findings, for women starting HRT at age 50 and taking it for 5 years, an extra 1 woman will be diagnosed with breast cancer between age 50 and 59 years for every:

  • 50 women taking continuous combined HRT.
  • 70 women taking combined monthly cyclical HRT.
  • 200 women taking oestrogen only HRT.

Other significant findings were:

  • The risk of developing DVT drops after stopping HRT, but women who have taken HRT are at some increased risk of breast cancer for at least 10 years after stopping.
  • The risk of breast cancer was also increased among women in their 40s taking HRT, but in real terms this risk is lower because fewer women develop breast cancer at this age. It must be remembered that current guidance is to offer HRT to all women going through the menopause before the age of 45, because HRT helps protect against osteoporosis: women going through the menopause under the age of 45 are at higher risk of osteoporosis,

You can find out more about the findings of this study in the 'further reading' section below.

Breast cancer. You may have a small increased risk of breast cancer if you take combined (oestrogen and progestogen) HRT. This risk increases the longer you have used HRT. When you stop taking HRT, you have the same risk of breast cancer as someone who has not taken HRT. The actual risk of breast cancer with taking HRT is actually very small. It equates to around one extra case of breast cancer per 1,000 women each year. Most of the studies done in this area have not actually shown an increased risk of breast cancer in women who take HRT for five years or less.  Note: there is no increased risk of breast cancer in women who take HRT under the age of 50 years.

Stroke. Some studies have shown that there is a small increased risk of stroke in women taking either oestrogen-only or combined HRT. However, there is no increased risk of stroke in women who use the patch (or gel) rather than tablets. HRT containing lower doses of oestrogen seems to be associated with a lower risk of stroke compared to those containing higher doses.

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.

Further reading and references

  • Panay N et al; British Menopause Society & Women’s Heath Concern recommendations on hormone replacement therapy, May 2013

  • Menopause: diagnosis and management; NICE Guideline (November 2015 - last updated December 2019)

  • Kaunitz AM, Manson JE; Management of Menopausal Symptoms. Obstet Gynecol. 2015 Oct126(4):859-76. doi: 10.1097/AOG.0000000000001058.

  • Contraception for Women Aged over 40 Years; Faculty of Sexual and Reproductive Healthcare (2017 - last updated September 2019)

  • No authors listed; Nonhormonal management of menopause-associated vasomotor symptoms: 2015 position statement of The North American Menopause Society. Menopause. 2015 Nov22(11):1155-74. doi: 10.1097/GME.0000000000000546.

  • Langer RD; The evidence base for HRT: what can we believe? Climacteric. 2017 Apr20(2):91-96. doi: 10.1080/13697137.2017.1280251. Epub 2017 Mar 10.

  • Type and timing of HRT and breast cancer risk; The Lancet, August 2019