Hormone replacement therapy (HRT)

Published by Bupa's Health Information Team, June 2010.

This factsheet is for women who are taking hormone replacement therapy (HRT), or anyone who would like information about it.

During the menopause, the levels of the hormone oestrogen naturally start to decrease. This reduction in oestrogen causes the symptoms usually associated with the menopause.

About HRT

Hormone replacement therapy (HRT) is a treatment used to reduce the symptoms of the menopause. The menopause is when your periods permanently stop. It's a natural part of ageing and happens when your ovaries stop releasing eggs as a result of falling levels of oestrogen. The aim of HRT is to top up or restore your body's supply of hormones.

Why would I take HRT?

Your ovaries make the hormones oestrogen and progesterone as part of the menstrual cycle. During the menopause, your levels of oestrogen will fall. Low oestrogen levels cause the symptoms of menopause, such as:

• hot flushes
  
• night sweats
  
• headaches
  
• vaginal dryness
  
• urinary infections
  
• mood swings

Low oestrogen levels can also weaken your bones, which may cause them to break more easily (a condition called osteoporosis). Taking HRT treatment helps to reduce the symptoms of the menopause.

What are the main types of HRT?

There are two types of HRT: combined HRT and oestrogen-only HRT. Your GP will discuss your options with you.

If you're going through the menopause and have not had a total hysterectomy (an operation to remove your womb) you will need to take a combination of oestrogen and progesterone (combined HRT). Even if you have had a partial hysterectomy you may still have some of your womb lining present. This means you might need to take both hormones. These two hormones usually work together during your menstrual cycle. Oestrogen stimulates the production of your womb lining (endometrium) and the release of an egg. Progesterone stimulates your womb to shed its lining, causing you to have a period. If there is no progesterone to stimulate a period or if you take oestrogen on its own, this can lead to uncontrolled growth of the lining of the womb and increase your risk of developing womb cancer.

If you have had a hysterectomy to remove your womb, you're at no risk of endometrial cancer and can take oestrogen on its own.

How to take HRT

You can take HRT in a number of different ways, depending on your medical history and what suits you.

• Continuous oestrogen and cyclical progesterone. This means taking oestrogen every day and adding progesterone for 10 to 14 days in a month to mimic the menstrual cycle. You will usually have a period at the end of each course of progesterone.
  
• Continuous oestrogen and progesterone. This means taking both oestrogen and progesterone every day and will stop you having a period. However, this is only recommended for women who have been postmenopausal for at least a year. If you are taking HRT in this way, you may notice some irregular bleeding for the first year.
  
• Continuous oestrogen. This is only suitable for women who have had a total hysterectomy.
  
• Cyclical oestrogen. This means taking oestrogen every day for three out of four weeks. It's not recommended because your menopause symptoms may come back during the week when you aren't taking tablets.

There are a number of different methods of taking HRT including:

• tablets that you take daily
  
• skin patches that you put on the bottom of your back once or twice a week
  
• gel that you put on your arms and shoulders or inner thigh every day
  
• a pessary (a small tablet that is inserted into the vagina) or vaginal ring
  
• a nasal spray

Your GP may recommend you have an HRT implant. This is a small pellet containing oestrogen. Your GP will insert it under the skin of your abdomen, buttock or thigh. The implant slowly dissolves, causing oestrogen to be absorbed into your blood. It lasts for between two and 12 months, depending on the strength of the implant. After this time, you will need to get your implant replaced.

Your GP will talk to you about your options and help you choose how to take your HRT.

Special care

Your GP won't usually prescribe HRT if you have breast or endometrial cancer, or a have had breast cancer, angina, blood clots, liver disease or abnormal vaginal bleeding in the past. This is because HRT can increase your risk of having a stroke, developing breast or ovarian cancer and blood clots. If you're concerned, talk to your GP about your options.

Side-effects of HRT

The side-effects of HRT can include:

• breast tenderness
  
• leg cramps
  
• headaches
  
• feeling sick
  
• bloating
  
• fluid retention - this is when fluid builds up in your ankles or face, which can cause some swelling

There is not enough evidence to suggest that HRT makes you put on weight. Many women gain weight when they reach the menopause. This weight gain may be your body's way of producing more oestrogen, as your body fat produces some oestrogen after the menopause.

Most side-effects get better within a couple of months. If the side-effects don't improve, your GP may suggest you try a different oestrogen or progesterone, depending on what is causing your side-effects.

You're at a slightly increased risk of having a stroke and of developing breast or ovarian cancer or blood clots if you take HRT. The risks are small, but your GP will talk to you about them before starting any treatment.

If you're taking HRT, it's important to have regular mammograms and be breast aware. This means knowing how your breasts look and feel, and knowing what changes to look out for. If you're worried about any changes to your breasts, see your GP straight away.

Complications from HRT are rare, but see your GP if you have:

• severe chest pain or sudden breathlessness
  
• severe stomach pain
  
• severe headache
  
• changes to your vision or hearing
  
• swelling or pain in one of your calves

Resistance to HRT

When you take a medicine repeatedly or for a long period of time, you can become resistant to it. This means the more you take it, the less effect it has or the shorter this effect lasts. However, this usually only happens if you have an HRT implant.

Names of common HRT treatments

Examples of the main types of HRT treatments are shown in the table. The type of HRT treatment your GP prescribes will depend on your medical history and what type of HRT suits you best.

You may have noticed that your medicine has two or more names. All medicines have a generic name, which is its official medical name. Many medicines also have at least one brand name, which is the trade name. Generic names are written in lower case and brand names start with a capital letter.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.