Like any medication, the hormones used in hormone replacement therapy (HRT) can sometimes have side effects.

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

Speak to your GP if you experience severe side effects or they continue for longer than three months.

This page covers:

Side effects of oestrogen

Side effects of progestogen

Weight gain and HRT

More serious risks

Side effects of oestrogen

The main side effects associated with taking oestrogen include:

  • bloating
  • breast tenderness or swelling
  • swelling in other parts of the body
  • nausea
  • leg cramps
  • headaches 
  • indigestion 
  • vaginal bleeding

These side effects will often pass in a few weeks, but the following measures may help relieve some of them in the meantime:

  • taking your oestrogen dose with food may help to reduce nausea and indigestion
  • eating a low-fat, high-carbohydrate diet may reduce breast tenderness
  • regular exercise and stretching may help reduce leg cramps

If side effects persist, your GP may recommend switching to a different way of taking oestrogen (for example, changing from a tablet to a patch), changing the specific medication you're taking, or lowering your dose. 

Side effects of progestogen

The main side effects associated with taking progestogen include:

As with side effects of oestrogen, these will usually pass in a few weeks,

If they persist, your GP may recommend switching to a different way of taking progestogen, changing the specific medication you're taking, or lowering your dose. 

Weight gain and HRT

Many women believe that taking HRT will make them put on weight, but there's no evidence to support this claim.

You may gain some weight during the menopause, but this often happens regardless of whether you take HRT.

Exercising regularly and eating a healthy diet should help you to lose any unwanted weight.

More serious risks

HRT has also been associated with some more serious risks, such as an increased risk of blood clots and certain types of cancer.

Read about the risks of HRT for more information.

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: 20/07/2016

Next review due: 20/07/2019