Hormone replacement therapy (HRT) – is it for me?
Find out more about the different types of HRT, as well as the benefits and risks of treatment.
Hormone replacement therapy (HRT) can be an extremely effective way of managing the many symptoms of menopause. It also provides some long-term benefits for women, like reducing the risk of osteoporosis (thinning bones).
But many women feel anxious about starting HRT, usually because of the risks and possible side effects.
In this article, we provide a balanced view of the benefits and risks of HRT so that you can make an informed decision. We also explore HRT alternatives if you decide that HRT isn’t for you.
In this article, we cover:
- How does HRT work?
- Types of HRT
- Ways of taking HRT
- How long do I need to take HRT for?
- How long does HRT take to work?
- Benefits of HRT
- Risks of HRT
- Who shouldn’t take HRT?
- Side effects of HRT
- Does HRT cause weight gain?
- Alternatives to HRT
- Blood testing while using HRT
How does HRT work?
The ovaries produce three main types of hormones:
- Oestrogens (e.g. oestradiol)
- Progestogens (e.g. progesterone)
- Androgens (e.g. testosterone)
During menopause, the levels of these hormones change – some more than others. Most symptoms of menopause are due to declining levels of oestrogen.
Put simply, HRT is a way of topping up your oestrogen levels to reduce symptoms and improve quality of life.
Note that testosterone replacement is beneficial for some women going through menopause. Find out more about the effects of low testosterone on menopause symptoms.
Types of HRT
HRT comes in two main forms: oestrogen-only HRT and combined HRT. What’s right for you will depend on your medical history and whether you still have periods.
Oestrogen-only HRT (oestrogen)
Your doctor will usually recommend oestrogen-only HRT if you’ve had your womb removed during a hysterectomy. This type of HRT is also suitable if you’re already taking a progestogen (for example, with a Mirena coil).
Combined HRT (oestrogen and progesterone)
If you still have a womb, your doctor is likely to recommend combined HRT. Taking both oestrogen and progesterone helps to reduce the risk of womb cancer by protecting the womb lining.
There are two ways you can take combined HRT:
- Continuous combined HRT – if your last period was over 12 months ago, you can start continuous combined HRT. With this regimen, you take oestrogen and progesterone together daily (with no monthly bleed). However, starting this too early may cause irregular bleeding.
- Sequential HRT – this is mainly for women whose last period was less than 6–12 months ago. You take oestrogen every day and progesterone taken with this for half of the month. This usually results in monthly withdrawal bleeds, similar to a period. It’s possible to reduce bleeding by using the Mirena coil.
Ways of taking HRT
There are many different forms of HRT. Each comes with its pros and cons.
How long do I need to take HRT for?
Based on a study of over 100,000 UK women, the average treatment duration for HRT is six years . Most women take HRT for between two and ten years. You may need to take HRT for longer, especially if you started menopause before the age of 40.
How long does HRT take to work?
It can take a few weeks before you notice the benefits of HRT, and up to a few months before you feel the full effects. If, after a maximum of three months, your symptoms are not improving, it’s worth speaking to your doctor. They may advise increasing your dose or trying an alternative.
Benefits of HRT
HRT can be life-changing. For some women, it can drastically improve symptoms and help them feel more in control. Generally, the benefits of HRT far outweigh the risks.
HRT can help improve the following symptoms:
- Hot flushes
- Night sweats
- Vaginal dryness and painful sex
- Joint and muscle aches
- Low mood and anxiety
- Low libido
- Brain fog and memory issues
HRT and osteoporosis
HRT can help to keep your bones healthy, reducing the risk of osteoporosis (thinning bones) and fractures. For women who start menopause before the age of 40 (premature ovarian insufficiency), HRT can be particularly beneficial.
HRT and heart disease
HRT is not thought to increase heart disease risk when started in women under 60. And oestrogen-only HRT may even slightly reduce the risk of heart disease .
Risks of HRT
The risks of HRT are generally very low but vary from woman to woman.
Factors that may affect your risk of adverse effects when taking HRT include:
- Your age – the risks of HRT increase as you get older
- Treatment duration – e.g. taking HRT for ten years instead of five increases your risk
- Your weight
- Whether you smoke
- How much alcohol you drink
- Underlying medical conditions
- Your family history
HRT can increase the risk of some conditions. It’s important to note that the risks of these conditions are quite low for people who don’t take HRT. HRT only slightly increases these risks. You can minimise your risk further by maintaining a healthy lifestyle and stopping HRT as soon as you’re able to.
Both types of HRT can slightly increase the risk of breast cancer if used for longer than one year. The risk is related to the treatment duration and may persist for more than 10 years after stopping. The risk of breast cancer is highest in women over 60, who use continuous combined HRT for long periods.
There is no increased risk of breast cancer with vaginal oestrogen treatments .
If you have a womb and take oestrogen-only HRT, there is an increased risk of endometrial cancer. That’s why it’s important to take a progestogen alongside oestrogen, such as a Mirena coil, to reduce your risk. Or, it's prescribed to women who are not at risk of endometrial cancer.
If you use vaginal oestrogen, you don’t need to take a progestogen.
Some studies have shown a link between HRT and some types of ovarian cancer, but this risk is very low. And there’s no evidence that HRT will increase your risk of dying from ovarian cancer.
Coronary heart disease
Combined HRT is associated with little or no increased risk of coronary heart disease (damage to the heart vessels). Oestrogen-only HRT is associated with no or reduced risk of coronary heart disease .
Oral oestrogen, but not transdermal oestrogen, can slightly increase the risk of stroke. For women under 60, this risk is very low.
Oral HRT (mainly combined HRT) may slightly increase the risk of blood clots.
Transdermal preparations, like creams and patches, do not carry this same risk.
To date, research on the association between HRT and dementia has been mixed. Some studies suggest that HRT can reduce dementia risk, while others state the opposite.
A 2021 analysis involving nearly 210,000 women found that HRT after menopause was associated with a lower risk of dementia . The effects varied depending on factors like type of medication, duration of treatment, and history of depression.
In contrast, a more recent Danish study tracking over 55,000 women found that combined HRT was associated with a 24% increase in the risk of dementia . But, many of these studies are observational. This means they can show a connection but cannot conclusively prove that HRT causes a change in the risk of dementia. There are many reasons this might be the case. For example, memory issues are a common symptom of menopause but can also be an early sign of dementia. If symptoms of early dementia are mistaken for menopause symptoms and HRT is prescribed, it may distort the data. Also, some studies don’t account for factors like social isolation, smoking, and dietary factors, which are known to be involved in the development of dementia.
More research is needed to fully understand the link between HRT and dementia. For now, it’s important to be aware that HRT should not be prescribed to reduce dementia risk.
Summary of risks
The following table is based on the MHRA’s updated guidance on the risks of HRT . The figures show the increased risk on top of the baseline risk, which varies according to age and treatment duration.
*Risk is lowest for sequential HRT compared with continuous combined HRT.
**Latest evidence suggests transdermal HRT products have a lower risk of blood clots than oral preparations.
Who shouldn't take HRT?
HRT isn’t suitable for everybody. That’s because the risks of HRT can sometimes outweigh the benefits.
HRT may be less suitable for you if have:
- A history of breast or ovarian cancer, or you’re at high risk of these conditions
- Recurrent or active endometrial cancer
- Abnormal vaginal bleeding that’s not been investigated
- A family history of blood clots or a history of recurrent blood clots
- A history of stroke
While smoking is not an absolute contraindication to HRT, it is a very good idea to stop. Smoking increases your risk of blood clots, which can make taking HRT more dangerous.
Side effects of HRT
It’s common to experience side effects when you start HRT, such as nausea, breast tenderness, or headaches. Side effects tend to settle within a few weeks to months. If not, discuss these with your GP, as there may be an alternative you can try.
Vaginal bleeding is a common side effect of HRT in the first three months for women with a womb. If this happens, let your GP know at your three-month review. If it’s after your three-month review, let them know promptly.
Other common side effects of HRT include:
- Leg cramps
- Breast tenderness
- Ankle swelling
- Mood changes
Does HRT cause weight gain?
You may gain weight during menopause and as you get older. But this often occurs whether you take HRT or not. There’s little evidence that HRT can make you put on weight.
Alternatives to HRT
If you decide HRT isn’t for you, there are plenty of alternatives.
Alternatives to HRT include:
- Lifestyle changes – adapting your lifestyle can be an effective way of managing your menopause symptoms. For example, it’s important to exercise regularly, have a healthy diet, cut down on caffeine and alcohol, and quit smoking.
- Cognitive behavioural therapy (CBT) – CBT is a form of talking therapy. It can be helpful for some menopause symptoms, including anxiety and stress.
- Antidepressants – antidepressants can help with both low mood and anxiety during menopause. The most commonly prescribed medications are selective serotonin reuptake inhibitors (SSRIs).
- Clonidine – Clonidine is a medication that can help to reduce hot flushes and night sweats. Note that it may cause side effects, such as dry mouth, low mood, and constipation.
- Fezolinetant – Fezolinetant is a new drug that’s proven effective at reducing the vasomotor symptoms of menopause, such as hot flushes . It’s likely to become available in the UK very soon.
- Herbal medicines – some herbs like black cohosh and red clover may help with menopause symptoms. Bear in mind that they work differently for everyone.
Blood testing while using HRT
If you have symptoms of menopause before the age of 45, blood testing can be helpful to confirm the diagnosis. Otherwise, your doctor will usually diagnose menopause based on your symptoms.
HRT dosing will depend on your symptoms (and not your hormone levels), so a blood test usually isn’t necessary. In fact, most clinical bodies, including the NHS and British Menopause Society, don't recommend it.
However, some women like to monitor their hormone levels, particularly if their symptoms haven't improved, to check if their HRT being absorbed. There’s also some evidence that maintaining adequate oestrogen levels helps reduce the risk of osteoporosis, especially in women who have gone through early menopause. In these cases, some sources suggest aiming for an oestradiol level of 200–600 pmol while taking HRT .
HRT – is it for me?
HRT can be a very effective treatment but it’s important to know about the potential risks.
Your GP can talk you through the options and help you decide what’s best for you.
Menopause Matters is also an excellent online resource. Alternatively, you can find an NHS or private menopause specialist near you for more advice.
- Akter N, Kulinskaya E, Steel N, Bakbergenuly I. The effect of hormone replacement therapy on the survival of UK women: a retrospective cohort study 1984−2017. BJOG. 2022;129: 994–1003. doi:10.1111/1471-0528.17008
- Recommendations | Menopause: diagnosis and management | Guidance | NICE. NICE. [cited 20 May 2023].
- Hormone replacement therapy (HRT): further information on the known increased risk of breast cancer with HRT and its persistence after stopping. In: GOV.UK [Internet]. [cited 10 Aug 2023].
- Kim H, Yoo J, Han K, Lee D-Y, Fava M, Mischoulon D, et al. Hormone therapy and the decreased risk of dementia in women with depression: a population-based cohort study. Alzheimer’s Research & Therapy. 2022;14: 83. doi:10.1186/s13195-022-01026-3
- Pourhadi N, Mørch LS, Holm EA, Torp-Pedersen C, Meaidi A. Menopausal hormone therapy and dementia: nationwide, nested case-control study. BMJ. 2023;381: e072770. doi:10.1136/bmj-2022-072770
- Lederman S, Ottery FD, Cano A, Santoro N, Shapiro M, Stute P, et al. Fezolinetant for treatment of moderate-to-severe vasomotor symptoms associated with menopause (SKYLIGHT 1): a phase 3 randomised controlled study. The Lancet. 2023;401: 1091–1102. doi:10.1016/S0140-6736(23)00085-5
- HRT Treatment Plans. Chelsea and Westminster Hospital NHS Foundation Trust. [cited 23 Aug 2023]