Bleeding is a common side effect when starting or changing HRT but it’s important to know what’s normal and when to seek help

When you first start taking HRT, you might be surprised to experience some bleeding.

This could be light spotting or a heavy period, it could come and go, or it could last a few weeks. Bleeding that happens outside your normal menstrual period is known as breakthrough bleeding. While it can be unsettling to experience breakthrough bleeding on HRT, it is a common side effect of the medication – it can affect up to 40% of women – and it is temporary.

If you are perimenopausal when you start taking HRT, your usual bleeding pattern might change, and if you are menopausal when you start, you might experience bleeding. In both cases, bleeding on HRT should settle down within six months. Similarly, if you change the dose or type of your HRT, you may experience bleeding, but again this should settle within three to six months.

While irregular bleeding is common in the first few months of starting HRT, you should speak to your Newson Clinic healthcare professional if you have been taking HRT for more than six months and experience unexpected bleeding. A change of dose or type might be required, or your Newson Clinic doctor may want to rule out any underlying causes of bleeding. It’s also important to seek advice if you are experiencing painful or heavy bleeding on HRT.

If you would like advice about bleeding or are wondering if HRT is right for you, you can book an appointment to speak to a Newson Clinic healthcare professional below.

What causes bleeding on HRT?

In the majority of women, bleeding on HRT is due to your body adjusting to the new hormone doses. Fluctuating or imbalanced hormones can cause bleeding – for example when oestrogen levels are high and progesterone is low. In perimenopause, your own hormone levels are fluctuating and when you have high or fluctuating levels of oestrogen, bleeding can occur.

What else can cause bleeding?

There are other causes of bleeding, including fibroids, which are non-cancerous growths that develop in or around your womb and are made up of muscle and fibrous tissue. About two in three women will develop at least one fibroid during their lifetime, usually between the ages of 30 and 50 [1].

Bleeding can also be caused by polyps or the thickening of your womb lining. Occasionally there might be a more serious cause so you should have bleeding checked [2].  If bleeding occurs more than a year since your last period, you should consult your Newson Clinic clinician.