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Side effects of hormone replacement therapy (HRT)

Like any medicine, the hormones used in hormone replacement therapy (HRT) can cause side effects. But it's common to have no side effects or only mild ones.

Any side effects usually improve over time, so it's a good idea to carry on with your treatment for at least 3 months if possible.

Side effects of HRT can be similar to menopause symptoms, so it might not be your HRT that's causing it.

There are different types of HRT and it can take time to find the right dose and type that works for you.

To help with side effects, a GP might suggest changing your dose, the type of HRT you take or how you take it. For example, switching from tablets to patches.

Non-urgent advice: Speak to a GP if:

  • you have severe side effects or they continue for longer than 3 months

Side effects of oestrogen

Side effects of taking oestrogen can include:

  • headaches
  • breast pain or tenderness
  • unexpected vaginal bleeding or spotting
  • feeling sick (nausea)
  • mood changes, including low mood or depression
  • leg cramps
  • mild rash or itching
  • diarrhoea
  • hair loss

They will often go away after a few weeks. There are things you can do to help cope with them.

Find out more about side effects of oestrogen and how to cope:

Side effects of progestogen

Side effects of progestogen can include:

  • changes in your periods, including spotting or bleeding between periods
  • headaches
  • breast pain or tenderness
  • feeling sick (nausea)
  • diarrhoea
  • feeling tired or dizzy
  • mood changes, including low mood or depression
  • mild rash or itchy skin
  • acne

As with side effects of oestrogen, these will usually go away after a few weeks. There are things you can do to help cope with them.

Find out more about side effects of Utrogestan (micronised progesterone) and how to cope

Side effects of combined HRT

If you take combined HRT you may get some of the side effects of oestrogen or those of progestogen.

Find out more about side effects of combined HRT and how to cope:

Side effects of tibolone

The common side effects of tibolone can include:

  • breast tenderness
  • stomach pain or pelvic pain
  • unusual hair growth
  • vaginal discharge, vaginal itching or thrush
  • vaginal bleeding

Find out more about side effects of tibolone and how to cope

Vaginal bleeding and HRT

It's common to have irregular vaginal bleeding or spotting in the first few months after you start taking HRT. This usually settles down within 6 months and is not usually a sign of anything serious.

If you take sequential combined HRT, or daily oestrogen with separate progestogen tablets for part of the month, it's normal to have withdrawal bleeding at the end of each course of progestogen.

If you take continuous combined HRT, it's common to have irregular vaginal bleeding or spotting in the first 4 to 6 months of taking it.

Tell a GP at your first review after 3 months if you're having irregular vaginal bleeding. If it does not go away, the GP might suggest changing your dose of progestogen.

Non-urgent advice: Speak to a GP if:

  • you have irregular vaginal bleeding for more than 6 months after you start taking HRT
  • your bleeding becomes heavier
  • you get vaginal bleeding after you have not had periods for a while

Weight gain and HRT

There's little evidence that most types of HRT make you put on weight.

You may gain some weight during the menopause and as you get older, but this often happens whether you take HRT or not.

Exercising regularly and eating a balanced diet should help you to manage your weight.

More serious risks

HRT has also been associated with a small increase in the risk of blood clots and breast cancer.

Find out more about the benefits and risks of HRT.

Reporting side effects

The Yellow Card scheme allows you to report suspected side effects from any type of medicine you are taking.

It's run by a medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA).

Page last reviewed: 3 January 2023
Next review due: 3 January 2026