Hormone Replacement Therapy, or HRT, is widely used for treatment of menopausal symptoms, and is considered by many to be the most effective. The aim of HRT, as its name would suggest, is to replace the hormone that the body ceases to produce during the menopause, namely oestrogen.
The common symptoms of the menopause are associated with a decrease of the body’s production of oestrogen, including night sweats, vaginal dryness, headaches, low mood, reduced sex drive, and the infamous hot flushes!
While the benefits of HRT are widely recognized, its unwanted side effects are the cause of much controversy, with some studies claiming it can increase the risk of cancer and heart disease. But first, let’s take a look at exactly what HRT is and how it works.
The Low-Down on HRT
HRT is available in all shapes and sizes, each designed to offer as wide a choice as possible to the menopausal woman. However, there is not only choice in the type and dose of hormones available, there is also choice in how these hormones are introduced to the body – or what doctors call “the route of delivery”. There are three main routes, and each will be appropriate for different women:
- Via the mouth as a tablet – this is the most common form of HRT
- ‘Transdermal’ (through the skin) methods are less common but still very popular. They can take the form of an adhesive patch, or a gel
- Finally as an implant injected beneath the skin to provide slow release of oestrogen over several months.
For vaginal and bladder symptoms, oestrogen can be taken as a small vaginal tablet, cream or vaginal ring inserted within the vagina to provide very “local” relief.
The type of HRT most suited to a woman will depend on a variety of factors, including her stage in the menopausal process, and whether or not she has had a hysterectomy. Most forms of HRT combine different amounts of the hormones oestrogen and progesterone (manufactured progesterone is called progestogen in the UK and progestin in the US).
There are over 50 different combinations of HRT currently available. Most women will make their choice over whether to take HRT, and which form, with the help of their GP. Here is a summary of the main forms:
The core ingredient of all forms of HRT is oestrogen. Oestrogen relieves hot flushes, prevents vaginal symptoms and maintains bone strength. The best HRT for women who have had a total hysterectomy, where the whole womb including its neck (cervix) has been removed, is oestrogen alone. Oestrogen alone can be taken as a daily tablet, a weekly or twice weekly patch, a daily gel or an implant. Varying doses of oestrogen are available. The new lower dose varieties aim to reduce the incidence of side effects while maintaining symptom relief and bone strength.
Oestrogen & Progestogen
Oestrogen-alone HRT can stimulate the lining of the womb (endometrium), leading to excess growth and possibly cancer. Therefore for women who have not had a hysterectomy, a second hormone is also prescribed (progestogen) to counteract the effects of oestrogen and protect the endometrium. Oestrogen plus progestogen is known as ‘combined HRT’.
In women who have had a partial hysterectomy (with cervix intact), some womb lining (endometrium) may still remain, so progestogen may be required with the oestrogen. For women who are known to have endometriosis a continuous combined HRT is recommended (see below). Women who have had an endometrial ablation (an operation to remove the lining of the womb which is often performed for very heavy periods) should also receive progestogen in case any part of the endometrium is left. Combined HRT is available in the form of either a tablet or a patch.
The way in which progestogen is taken along with the oestrogen determines whether or not the HRT will lead to bleeding. By adding progestogen for 10 to 14 days a month, a bleed occurs in the days following this course, similar to that of a natural cycle. This form of ‘cyclical’ or ‘sequential HRT’ is still used in peri-menopausal women and during the first year or two after the menopause.
Forms of hormone replacement that give continuous progestogen with the oestrogen have been developed to avoid bleeding altogether. This method is called ‘continuous combined HRT’ and is thought to reduce the risk of endometrial cancer even more so than sequential HRT. If you have had at least a year without periods and are thought to be postmenopausal, continuous combined HRT can be used.
This table shows how the timing of progestogen will affect bleeding:
|10-14 days in a month
|14 days every 13 weeks
||Bleeds every 3 months
The first “bleed-free” HRT contained a synthetic hormone known as Tibolone which, when taken every day, had the combined effects of oestrogen, progestogen and testosterone. Tibolone relieves menopausal symptoms, prevents bone loss, and may improve interest in sex. Tibolone, like other continuous therapies, is normally prescribed at least 12 months after the last menstrual period, so many women switch to these continuous types after taking a sequential HRT. Tibolone has also been shown to be particularly useful in women who are known to have endometriosis and fibroids as it does not appear to stimulate these conditions.
Help in knowing whether you are postmenopausal
Choosing an HRT is difficult enough, and can be even more complicated if you are unsure whether you are still in the early stages of menopause (‘perimenopause’) or whether your own menstrual cycle has stopped and you are in stage of post-menopause.
- Age: 80% of women are postmenopausal by the age of 54
- If your periods stopped at an early stage
- If blood tests have showed raised levels of Follicle Stimulating Hormone (FSH)
Side effects associated with HRT
As with any drug, there are known short-term and usually mild side effects from HRT which may trouble some women, especially in the first few months of use. These may include breast tenderness, leg cramps, nausea, bloatedness, irritability and depression. These side effects are related to oestrogen or progestogen, and may be overcome by a change of dosage, ingredients or route in the HRT prescribed.
Irregular bleeding or spotting can occur during the first 4-6 months of taking continuous combined HRT or Tibolone, and is not a cause for alarm. However, you should consult your doctor if you get heavy (rather than light) bleeding, if it lasts for more than six months, or if bleeding starts suddenly after some time without bleeding. Irregular bleeding may sometimes be improved by changing the type or route of HRT.
Treating local symptoms without raising hormone levels throughout the body
Some women do not wish to use, or cannot take, systemic HRT in any form which raises hormone levels throughout the body, but they still appreciate the relief of symptoms such as dry vagina and urinary problems. In this case, oestrogens can be given locally to the vagina in the form of a low dose cream, tablet or ring. These preparations raise local hormone levels but do not affect the whole body. Progestogen is not needed, since these local doses of oestrogen do not affect the endometrium. Local treatments often need to be taken on a long-term basis as symptoms often return when treatment is stopped.
The HRT Controversy
Concerns over increased risks of breast cancer, ovarian cancer and heart disease remain controversial and are the object of much scientific discussion. You can read more about this in our leaflet ‘HRT: What you should know about the risks and benefits’. If you are concerned about taking HRT you should talk to your healthcare practitioner, or alternatively phone the WHC Nurse Advice Line.
The next step
It is important to remember that the choice of whether or not to take HRT is in your hands. This fact sheet aims to help you understand all the HRT-related options available to you. However, there are other ways of dealing with menopausal symptoms that can be used either alongside HRT or instead of it. To read more about these, please see our factsheet on Complementary/alternative therapies for menopausal women.