HRT Risks and Benefits - Stella
12 mins

HRT risks and benefits

byDr. Lucy Wilkinson

Hormone replacement therapy (HRT) is the most effective proven treatment for many menopause symptoms. Yet there is an almost overwhelming amount of information out there – some of it conflicting. Inevitably, there are many myths and misunderstandings around HRT. It can even be difficult for medical professionals to make sense of the ever-changing recommendations.

Dr Lucy Wilkinson looks into the facts and evidence and answers your questions on the pros and cons of HRT, helping you to be better informed.

Start your free online menopause assessment to see if HRT is right for you

What is HRT?

Hormone replacement therapy (HRT) is a treatment for menopause symptoms. It comes in the form of pills, patches, creams and gels among others. It has been consistently proven to be an effective treatment for a range of menopause symptoms.

As suggested by the name, HRT works by replacing the hormones that are no longer produced by your body at the time of menopause. Since many symptoms of menopause are caused by this dramatic hormone reduction, taking HRT is a logical way to treat them.

Read our guide to body identical and bioidentical hormones.

However, this is not the whole story.

While HRT is an excellent treatment for menopause symptoms, it’s not the only thing to consider. 

First of all, it’s important to be sure of the diagnosis. Other medical issues can mimic menopause. As just one example, thyroid issues can cause hot sweats, mood changes and poor sleep – and can be treated easily with the right medication. This is why it’s important to see your doctor and discuss your symptoms before considering HRT.

HRT doesn’t work in the same way for every woman. Menopause symptoms are caused by hormone changes – but the way we experience them is much more complex. Factors like mental health, lifestyle and other medical conditions can all have an impact. This means that HRT will work differently for every woman who takes it.

Understanding your menopause journey

Menopause is best understood as a journey rather than a destination. For most women this journey lasts about 10 years, although it’s different for everyone.

It is common to start noticing symptoms between age 40 to 45. These frequently include hot flushes, disrupted sleep, tiredness, brain fog and mood changes. You may also notice that your periods become irregular or less frequent, even heavier.

Menopause can be very different from one person to the next. Some women have minimal symptoms, whereas others may find them very disruptive.

Menopause is best understood as a journey rather than a destination.”

Dr Lucy Wilkinson

Your symptoms will change over that 10-year period as your body adjusts to the hormonal changes. You may find that your symptoms wax and wane, or that new symptoms arise just when you least expect them – and that’s normal (if annoying!).

It is very difficult to predict when you will go through menopause, although a few factors including family history, illness and medication can have an impact. Going through menopause before the age of 45 is considered an early menopause. 

Read our essential guide to early and premature menopause here.

How do you know if you need HRT?

Ultimately this is a personal choice and depends on how your symptoms are affecting you. Many women manage their menopause without any form of treatment, while others find HRT helpful.

This is often a tricky decision to make. Menopause symptoms can be vague and develop over years, making it difficult to describe exactly how they are affecting you. If this is the case, keeping a diary or using a menopause symptom tracker may help you to get an objective overview.  

If your menopause symptoms are having a significant impact on your quality of life, are disrupting your daily activities or are not responding to lifestyle changes, it is a good idea to at least think about HRT. 

There are also a wide range of non-hormonal treatments and lifestyle changes that you may find useful, from dietary changes to exercise plans. The Stella app offers a personalised plan to help guide you through lifestyle changes to help manage symptoms.

The exception to this is if you’ve been through early menopause. In this case, your doctor is likely to recommend that you take HRT until the average age of menopause, which is 51 in the UK. This is to reduce your risk of osteoporosis and cardiovascular disease, as going through menopause early means you spend longer without the protective effects of oestrogen.

Do menopause symptoms require long-term treatment?

It is your choice whether you treat your menopause symptoms or not. If you want to stop HRT for any reason, speak to your doctor and they will be able to advise you.

Most symptoms eventually improve as your body adjusts to the new, lower level of hormones. Many women are therefore able to stop taking HRT after a few years.

The only group of menopause symptoms which tend to need longer-term treatment are known as genitourinary syndrome of menopause (GSM). These changes include vaginal discomfort, dryness, painful sex and urinary symptoms, and are caused by persistently low oestrogen levels. 

GSM can be treated very effectively using oestrogen creams, gels or pessaries applied directly to the affected area (also known as topical HRT). It is common to need ongoing treatment for many years after your other menopause symptoms have disappeared. Thanks to the low-risk nature of this sort of HRT, this is safe and effective in practice. 

How long does HRT take to work?

Don’t be disappointed if it doesn’t work straight away. It can take a few weeks for your symptoms to start improving and it’s common to have some side effects initially.

It can take anywhere from six weeks to three months to see how your body will react to the HRT. After this amount of time, you should have a good idea as to how much your symptoms will improve and whether any of those pesky side effects will stick around.

Your doctor should review your progress after three months. They will want to know how your symptoms are responding to the HRT, whether you have any side effects and whether your health has otherwise changed since you started the prescription (e.g. new medical conditions or medications).

If things aren’t going so well at this point, you may want to discuss changing your HRT. This can include changes to the dose or type of HRT you take. Your doctor will be able to advise on the best choices for you.

Find out more about what to expect from your HRT.

Can you have HRT?

While using HRT is a personal choice, there are certain circumstances in which your doctor will advise against it. 

These are due to pre-existing conditions which mean that HRT is riskier for you than for others.

Doctors are currently advised not to prescribe HRT if you have any of the following:

  • Breast cancer, whether past, present or suspected
  • Known or suspected oestrogen-dependent cancers (meaning those which grow in response to oestrogen, most often in the breast, ovary, womb or endometrium)
  • Unexplained vaginal bleeding (including irregular periods, bleeding in between periods, bleeding after sex or unexplained heavy bleeding)
  • Untreated endometrial hyperplasia (abnormal thickening of the lining of the womb)
  • Certain types of venous thromboembolism (blood clots) including pulmonary embolism (PE) and deep vein thrombosis (DVT), unless you are already on medications to thin the blood (anticoagulants)
  • Certain types of arterial disease including angina or myocardial infarction (heart attack), whether past or present
  • Liver disease with abnormal blood tests
  • Pregnancy 
  • Thrombophilic disorders (conditions which increase your blood’s tendency to clot)

They are also advised to prescribe only with caution in a number of conditions, including:

  • If you have risk factors for venous thromboembolism (blood clots including DVT or PE). These include being aged over 60, smoking, having a raised BMI or a history of cancer among others
  • Migraine
  • Diabetes mellitus
  • Increased risk of breast cancer (for example, if you have a strong family history or carry a BRCA gene)
  • Having a history of endometrial hyperplasia (abnormal thickening of the lining of the womb)
  • Porphyria cutanea tarda

Prescribing ‘with caution’ is generally done at your doctor’s discretion, and after weighing up your overall health and specific risk factors. Your doctor may want to monitor you more closely, or choose a type of HRT specifically to minimise your risks. They may also advise that HRT is too risky in your personal circumstances. If this is the case, take a look at the many treatment options that are available to you besides HRT. Good nutrition, exercise and stress management can all have a positive effect on menopause symptoms and can be personalised through your plan on the Stella app.  

HRT risks and benefits  

Why is HRT controversial?

While an effective treatment for menopause symptoms, HRT is not without controversy. 

In the early 2000s one of the earliest, large-scale research studies into the long-term safety of HRT (the Women’s Health Initiative study, published in 2002) concluded that this form of treatment came with more risks than benefits. Specifically, the earliest data published seemed to demonstrate an increased risk of breast cancer and coronary heart disease.

This understandably caused a wave of concern throughout the media and the medical community alike. Many patients stopped taking HRT, and many doctors stopped prescribing it.

However, a closer look at the study results showed that the reality was not as clear-cut as originally thought. This was in part due to the design of the study, which only included a very limited number of HRT preparations. Further analysis also showed that the majority of the women included in the study were over a decade past their last period, so it was unclear whether the conclusions of this study could be applied to younger women – who are often the ones taking HRT.

Read more about common HRT myths and find out the facts.

Recent studies

Over the following years, many studies have been done to investigate further. Thanks to this, we now have a much better understanding of the risks of HRT and the concerns identified at the turn of the millennium have largely been settled.

As well as having more information about HRT, we also have access to very different medications compared with those included in the study 20 years ago. Transdermal HRT – in the form of patches or hormone gels applied to the skin – is known to be much lower risk than those medications studied in the Women’s Health Initiative study, and is now widely used. We also have access to more body identical hormones, as opposed to the riskier conjugated oestrogens used in the past. 

While this is not to say that the risks of HRT can be ignored, they are now much better understood and can be weighed more accurately against the benefits of this useful and popular treatment.

What are the benefits of HRT?

The biggest benefit of HRT is that it provides the most effective available treatment of menopausal symptoms including:

Long-term health impact

Osteoporosis: Osteoporosis affects 1 in 3 women. The thinning of the bones associated with this condition makes fractures – even without a significant fall or injury – more likely. There is evidence that HRT protects your bone density, reduces the risk of so-called fragility fractures and prevents osteoporosis, especially if you have been through an early menopause. This benefit continues throughout the time you take HRT.

Find out more about osteoporosis and bone health in menopause.

Heart disease: In addition, there is some evidence that HRT may be beneficial for heart health. Women who start oestrogen-only or combined HRT before age 60 or within 10 years of their last period may have a reduced risk of both coronary heart disease and death from cardiovascular disease. One Danish study of over a thousand women found that the risk of coronary heart disease decreased by 50%. This protective effect only seems to happen for women who begin HRT within the earlier years of their menopause, sometimes referred to as the ‘window of opportunity’ theory. 

Despite these findings, the British Menopause Society’s (BMS) current stance is that evidence is not yet strong enough to confirm this effect. This means that while a reduced risk of heart disease may be a welcome side effect of HRT when used to control your menopausal symptoms, it is not recommended that you start HRT solely for this reason.

Bowel cancer: A number of studies – including this large 2017 study – have found that women taking combined HRT have a reduced risk of bowel cancer. However, evidence is still emerging and there are a number of questions still to be answered (including about the doses and types of HRT that produce this effect). Just as for heart disease, this is therefore a potentially beneficial side effect rather than a primary reason to take HRT.

Sarcopenia: This is the gradual reduction in muscle mass and strength that happens as we age. HRT is thought to improve this, but the effect is still unproven.

What are the risks of HRT?

As with all medications, HRT comes with certain risks. As mentioned earlier, the medical community is constantly learning about the extent of these risks, as well as the different ways we can protect against them. It’s important to have a thorough conversation with your doctor so that they can assess your risk profile. This will help you make a fully informed decision about the HRT that is right for you. 

Let’s take a look at the risks of HRT today…

Start your free online menopause assessment to see if HRT is right for you

Does HRT cause breast cancer?

Oestrogen-only HRT causes little or no change to your risk of breast cancer.

Similarly, vaginal oestrogens (used to treat genitourinary syndrome of menopause) are not associated with an increased risk of breast cancer. 

While that is good news for those on oestrogen-only HRT, it doesn’t hold true for all forms of HRT. It is thought that another commonly used type of HRT – combined HRT, containing both oestrogen and progesterone – may be associated with an increased risk. But what does that mean exactly? 

Breast cancer statistics

One way of understanding the statistics is to take an imaginary population of 1,000 women.

We know that among women aged between 50 and 59, we would on average expect to see 23 cases of breast cancer among those 1,000 women. This is known as your baseline risk.

If we were to give combined HRT to all 1,000 of those women, an extra four would develop breast cancer within the next five years (giving a total of 27 women per 1,000). 

While these risks should be taken seriously, it is important to take them in the context of cancer risk in the real world. 

For example, if those 1,000 women drank two or more units of alcohol per day, we would expect to see an extra five cases of breast cancer within the next five years. This gives a total of 28 cases per 1,000 women – a greater increase than that seen with taking combined HRT.

Likewise, we would see an additional three cases per 1,000 if all 1,000 of the women were smokers and a worrying 24 extra cases per 1,000 if all of the women were either overweight or obese.

As you can see, the increased risks of HRT are worth bearing in mind. However, this discussion should also be a starting point for thinking about a generally healthy lifestyle, and reducing other risk factors where possible. 

If you would like to see more statistics on this topic, take a look at this leaflet from Women’s Health Concern and this MHRA table, which summarises the data around the risks of HRT.

Does HRT cause blood clots?

It depends on the type of HRT you are prescribed.

When we talk about blood clots in HRT, we generally mean those that form in the deep veins of the body. The medical term for this is venous thromboembolism (VTE), and this group of conditions includes pulmonary embolism (PE) and deep vein thrombosis (DVT). 

Oral HRT does come with an increased risk of blood clots. The exact amount of increased risk varies between the different types of hormone in the HRT preparation, so the manufacturer’s leaflet is the best place to look for specific details on your prescription. 

One study found that the highest-risk preparation of oral HRT caused the risk to approximately double, while the lowest-risk preparation included in the trial caused an increase of just below 20%. As the background risk of having a blood clot is 1.7 in 1,000 over the age of 50, the overall risk is still relatively low.

Transdermal HRT (patches, gels or sprays) and vaginal HRT (vaginal gels, creams and pessaries) are not associated with an increased risk. This happens because of the way the hormones are absorbed through the skin and directly into the bloodstream. Your doctor is likely to recommend a transdermal preparation as a first choice, especially if you have any other risk factors.

Does HRT increase your risk of stroke?

Oral HRT is known to increase the risk of stroke when started in women over the age of 60. 

Transdermal and vaginal HRT are not associated with this increased risk. If you have any risk factors for stroke, your GP may therefore recommend a transdermal type of HRT if suitable.

Which HRT is best for you?

The best prescription is one that controls your symptoms with the lowest possible amount of risk. It can be tricky to find the right one, but your doctor will be able to advise on the best preparation for your individual circumstances.

When recommending any type of HRT, your doctor will be asking themselves two questions:

  • Which hormones do you need? 
  • What is the best way to supply them?

Which hormones do you need?

All forms of HRT should supply you with some form of oestrogen, as this is the hormone which will help ease your menopause symptoms (thanks, oestrogen!)  Your doctor will usually recommend trying a lower dose to begin with, although this can be increased if needed at follow-up appointments.

However, if you still have your womb, you need to take progesterone too. This is because oestrogen alone can cause abnormal thickening of the womb lining and even endometrial cancer. Progesterone has a protective effect which removes this risk.

You may also read about testosterone, which is sometimes prescribed as a gel and absorbed through the skin. This is used less frequently than standard HRT, but is sometimes recommended where loss of libido is an issue.

Find out more about testosterone for menopause.

How should you take your HRT?

In general, doctors tend to recommend starting with the lowest-risk preparation. These could be:

  • Vaginal oestrogen

If you only need help with vaginal and urinary symptoms, vaginal oestrogen will likely be recommended. This is particularly low risk given the type of oestrogen used and the fact that the hormone is not absorbed into your bloodstream (or only in very small amounts). Vaginal oestrogens do not affect the womb lining and can therefore be prescribed without adding in progesterone.

  • Patches, gels or sprays

If you need HRT to help with other symptoms of menopause, transdermal HRT is usually the lowest-risk option. This comes in the form of patches, gels or sprays. 

  • Hormonal Intrauterine Devices (hormonal IUDs)

Options include the Mirena, Levosert and Benilexa coils. A hormonal coil can be used to provide protective progesterone to your womb. They are often used alongside either transdermal or oral oestrogen.

  • Oral HRT

If you find the patches inconvenient or struggle with certain skin conditions, patches or gels may not be suitable and oral HRT may be best for you.

As you can see, there are plenty of options! Your own doctor will be able to advise on the best starting point for you.

How does HRT make you feel?

Hopefully a lot better! The majority of women who take HRT for menopause symptoms will start to see an improvement within a few weeks, although it can take several months to see the full benefit of treatment.

As with any medication, there are a few side effects to look out for.

What are the side effects of HRT?

The oestrogen in your HRT can cause:

  • Fluid retention 
  • Bloating
  • Tenderness and swelling of the breasts
  • Sensitive nipples
  • Headaches
  • Leg cramps
  • Indigestion

The progesterone in your HRT can cause:

  • Tender breasts
  • Fluid retention
  • Headaches
  • Mood swings
  • Depression
  • Breakouts and acne
  • Abdominal pain
  • Backache 

Take a look at the NHS for more details. Check in with your doctor if any of these are troublesome, severe or unexpected. They will be able to rule out any other possible causes that could be confused with side effects, and recommend any changes needed.

How long do HRT side effects last?

Side effects usually settle within a few months. You might need to go back to your doctor a few times to change the type, dose or preparation of your HRT if you are struggling or if side effects are lasting longer than anticipated. Your prescription can sometimes need a bit of fine-tuning – and that’s absolutely normal.

Talking to your GP about HRT

There is a huge amount of information about HRT out there. Being informed about your HRT risks and options is important, but where should you start?

Make sure to use a reputable source of information. These include:

Stella also has a wealth of information from clinicians and experts in specific areas

How long can you stay on HRT?

There is no set limit for how long you can stay on HRT. However, it’s important to check in for a review with your doctor every year once your treatment has been established.

Although your HRT prescription may stay the same over the years, you probably won’t! It is normal to collect new medical conditions, medications and risk factors as we age. These changes can mean that HRT is either no longer suitable for you, or that it is higher risk. Your doctor will want to discuss any changes at your annual reviews, and they may recommend changing or stopping HRT in some circumstances.

Can you take HRT over 60?

When you reach age 60, your doctor will probably want to have a more in-depth discussion about whether to continue HRT. By this age, your symptoms are likely to have settled down so stopping HRT may be a smooth transition.

Many women love their HRT – but don’t despair if you are advised to stop. HRT is just part of the picture when it comes to controlling your symptoms and living well through menopause.

Stella can help you make lifestyle changes, whether HRT is on the menu or not. Paying attention to diet, exercise and other lifestyle choices is every bit as important and can pave the way for a healthy later life.

Final word

Depending on what you read, HRT can be portrayed as either a danger to health or a wonder drug. The truth is that it’s neither. 

HRT is a useful part of our menopause toolkit, but it is not a one-size-fits-all solution to every menopause symptom. 

The fact that we are still learning about this treatment even after decades of prescribing it tells you that this is a complex and nuanced area. If you feel like HRT may be right for you, it’s a good idea to read around the subject and ask your doctor for their advice. They will be able to guide you to the best treatment for you personally – whether that is HRT or something else entirely.

Read more about menopause on our blog or in our symptoms library.

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