NICE guidance
The role of oestrogen






The word menopause refers to a woman’s last menstrual period, but the actual definition of being menopausal is when a woman has not had a period for one year.

The average age of the menopause in the UK is 51 years, but this can be earlier for some women. Symptoms of the perimenopasue often start at around 45 years of age. If the menopause occurs before the age of 40 it is classed as premature ovarian insufficiency (POI). If it occurs when a woman is under 45 years of age then it is called an early menopause.

Although the menopause is a normal event in a woman, certain conditions can bring it about earlier. These include an operation to remove the ovaries; radiotherapy to the pelvic area as a treatment for cancer, or if a patient has received certain types of chemotherapy drugs that treat cancer.1

If a woman has had a hysterectomy before her menopause, she can experience an early menopause, even if her ovaries are not removed. Although her ovaries will still make some oestrogen after the hysterectomy, it is common that the level of oestrogen will fall at an earlier age than average. As she will not have periods after a hysterectomy, it may not be clear when she is in ‘the menopause’. However, she may develop some typical symptoms when the level of oestrogen falls.


NICE guidance

The NICE guideline on menopause recommends hormone replacement therapy (HRT) as an effective option for treating menopause symptoms including hot flushes and night sweats. The decision on whether or not to take HRT or any other treatment depends entirely on the individual woman’s circumstances and the discussion with her doctor or nurse.2

The guideline clarifies the facts about the benefits and risks of taking HRT based on a thorough assessment of the evidence available. Individuals’ risks of specific outcomes will vary according to factors other than use of HRT, for example, lifestyle and personal or family medical history.

It recommends that menopausal women discuss with their doctors their own individual situation in relation to the clarified risks and benefits so that they can agree an option that is right for them.


The role of oestrogen

Hot flushes
Night sweats
Lack of libido
Poor sleep
Poor concentration
Weight/body “shape”
Heavy/light periods
Worsening premenstrual syndrome
Joint pains
Hair and skin changes
Poor memory
Headaches/worsening migraine
“Brain fog”
Vaginal dryness

The role of oestrogen on a woman’s body is widespread and can affect her physical shape, breasts, uterus and urethra, collagen, cardiovascular system, emotions and brain.

Around 80% of women will have symptoms related to the menopause and of these 25% will have severe symptoms. Half of women do not see their GP and a recent survey showed that 77% women did not realise their symptoms were due to the menopause. There are many myths surrounding management of the menopause. Here are some of the more common ones:

The menopause only lasts a year or two so women should just put up with their symptoms

The average length of time is four years and many women still have some symptoms for longer than ten years. Symptoms include hot flushes, night sweats, tiredness, lack of libido, poor sleep, poor concentration and weight/body shape issues. Some women will also experience heavy or light periods, worsening premenstrual syndrome, joint pains, hair and skin changes, poor memory, headaches/worsening migraine, palpitations and “brain fog.”

Menopause can also have a psychological impact in the form of anxiety, panic attacks, feeling low, mood swings, feeling frustrated and tearful.


All women with menopausal symptoms need to have their follicle-stimulating hormone (FSH) levels undertaken to diagnose their menopause

No tests are needed in otherwise healthy women over the age of 45 years with menopausal symptoms. This includes those in the perimenopause based on vasomotor symptoms and irregular periods; menopause in women who have not had a period for at least one year (not on contraception) and menopausal symptoms in those without a uterus. FSH tests should, however, be considered in those women that are aged between 40-45 years with menopausal symptoms and those who are under 40 years in whom menopause is suspected. Two FSH levels should be taken at least six weeks apart.


Women with a past history of DVT cannot take HRT

There is an increased risk of venous thromboembolism (VTE) in those women taking oral oestrogen and this risk is approximately double the normal population. It is, however, far lower than taking the combined oral contraceptive pill or with pregnancy. This background risk of VTE increases with increasing age.

Transdermal oestrogen is not associated with increased risk of VTE. Oral preparations undergo first-pass hepatic metabolism so women with an increased with of VTE should be offered oestrogen as either a gel or patch.

Transdermal oestrogen should be used in patients who are obese, with diabetes, a history of migraine, gallbladder/liver problems or with a history of DVT.


HRT increases risk of heart disease in all women

Cardiovascular disease (CVD) is the commonest cause of death in women worldwide and the risk of CVD greatly increases after the menopause.

Women with POI have greater increased risk of CVD, but there is a lower incidence of CVD in women taking HRT within ten years of their menopause. CVD benefit of taking HRT is greatest the earlier a woman starts HRT and there is a“window of opportunity” when HRT can lower cholesterol.

Underlying cardiovascular risk factors should also be managed such as blood pressure and cholesterol.

Evidence from systematic reviews of observational studies suggests that HRT may have beneficial effects in reducing the incidence of CVD events in postmenopausal women, but the results of randomised controlled trials have had mixed results.3

In one study, the objective was to assess the effects of HRT for the prevention of CVD in post-menopausal women, and whether there are differential effects between use in primary or secondary prevention. Secondary aims were to undertake exploratory analyses to assess the impact of time since the menopause that treatment was commenced (≥10 years versus <10 years), and where these data were not available, use age of trial participants at baseline as a proxy (≥60 years of age versus <60 years of age); and assess the effects of length of time on treatment.

It found provide strong evidence that treatment with HRT in post-menopausal women overall, for either primary or secondary prevention of CVD events, has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

Antidepressants are a good alternative to HRT

Physicians need to ask the right questions of patients as low mood, symptoms of depression and anxiety can also be symptoms of the menopause. HRT can be beneficial for low mood, but cognitive behavioural therapy should also be considered.

There is no clear evidence for selective serotonin reuptake inhibitors (SSRIs) or serotonin– norepinephrine reuptake inhibitors (SNRIs) to ease low mood. SSRIs and SNRIs or clonidine should not be offered as first-line treatment for vasomotor symptoms alone. However, when HRT is contraindicated then these medications may help to reduce hot flushes.


Panic attacks
Feeling low
Mood swings
Feeling frustrated
“I do not like what this has made me”
“Where have I gone?”
“I feel black most of the time”
“My zest for life has gone”
“I have never felt this low before”
“I feel like a dead person who is just existing”
  • CVD is the commonest cause of death in women worldwide
  • The risk of CVD greatly increases after the menopause
  • Women with POI have greatly increased risk of CVD
  • Lower incidence of CVD in women taking HRT within ten years of their menopause
  • CVD benefit of taking HRT is greatest the earlier a woman starts HRT
  • “Window of opportunity”
  • HRT can lower cholesterol
  • Manage any underlying cardiovascular risk factors (eg. blood pressure, cholesterol)

The maximum length of time a woman should take HRT is five years

Younger women need HRT until the age of 51 years and we need to assess risk/benefit for individuals with an annual review. Lower dose preparations may be beneficial for older women.

Topical oestrogen for symptoms of atrophic vaginitis should not be used in the long term

Local symptoms include vaginal irritation, vaginal dryness, soreness, increased frequency, increased urgency and symptoms of urine infections. Lowdose vaginal oestrogens are safe to use as long as needed and are safe on repeat prescription. It can be given with HRT and many women need lubricants/ moisturisers too.

There is an increased risk of breast cancer with all types of HRT

Breast cancer is common and there is an increased risk of breast cancer with increasing age, family history, obesity, alcohol and reduced exercise.

There is no increased risk of breast cancer in women who only take oestrogen and who are young. There appears to be lower risk with micronised progesterone and dydrogesterone and any increased risk reduces after stopping HRT. Modifiable risk factors need to be addressed.

HRT is associated with a risk of breast cancer in younger women with premature ovarian insufficiency

POI affects women under 40 years and around one in 100 women in the UK are diagnosed with POI. This diagnosis is often delayed and physicians should consider POI in younger women who have irregular or no periods. In women with POI, there is an increased risk heart disease, osteoporosis, psychological problems and reduced fertility.

HRT is not very effective at reducing osteoporosis risk

Osteoporosis affects around three million people in the UK and fragility fractures are more common in women than men. Over 1,200 people die every month in UK as a result of hip fracture. Also one year after a hip fracture, 60% will need help with daily activities and 80% will be dependent on other people.

Around one in two women over the age of 50 years will have a fragility fracture. Oestrogens are the most effective way of increasing bone mineral density and preventing osteoporotic fractures in addition to exercise, vitamin D and calcium.



Physicians should see the menopause as an opportunity. Medical intervention at this point in life offers women years of benefits from preventive healthcare.

The diagnosis of menopause is clinical and symptoms can be very debilitating. HRT is safe for most women under 60 years, but there is no maximum length of time for HRT. Women under 45 need to have HRT.

Transdermal HRT has the lowest risk of VTE/ stroke, but there is no increased risk of breast cancer with oestrogen only HRT.


GM editorial team

Conflict of interest: none declared




2. Menopause: diagnosis and management.

3. Boardman HM, Hartley L, Eisinga A, et al. Hormone therapy for preventing cardiovascular disease in postmenopausal women. Cochrane Database Syst Rev 2015; (3):CD002229