HRT (hormone replacement therapy): types, risks and review

The NHS describes HRT as a treatment that replaces the hormones oestrogen and progesterone, which fall to low levels as you approach the menopause. It is used to relieve hot flushes, night sweats, sleep problems, mood swings, anxiety and low mood, and vaginal dryness. The NHS says symptoms should improve within days or weeks. People over 45 with symptoms are advised to see a GP, and those under 45 should also seek advice because symptoms may point to early or premature menopause, when HRT is particularly important to protect bones.

It is not recommended if you have had certain cancers, blood clots, untreated high blood pressure or liver disease, or are pregnant. Whether it suits you is a prescriber decision.

Oestrogen comes as tablets, patches, gel, spray, and as vaginal rings, pessaries or cream. Progestogen can be taken as tablets or released by a Mirena coil, which the NHS says lasts up to five years. Combined HRT contains both. Oestrogen-only HRT is recommended only after a hysterectomy, because with a womb present, progestogen helps protect against womb cancer.

• Sequential combined HRT: oestrogen daily with progestogen for the last 10 to 14 days of a cycle, usually for perimenopause when periods continue.

• Continuous combined HRT: both hormones daily without breaks, usually once periods have stopped for a year.

• Vaginal oestrogen: low dose, treats dryness without needing progestogen, but does not treat hot flushes or mood.

• Tibolone: a daily tablet for post-menopause with combined hormone-like effects.

The NHS says HRT is effective at relieving most perimenopause and menopause symptoms, helps prevent bone thinning, and can improve muscle strength. It does not increase the risk of developing type 2 diabetes, and the NHS says there is no increased coronary heart disease risk, while the effect on dementia is unknown.

For breast cancer, the NHS says there are around five extra cases in every 1,000 women who take combined HRT for five years, with risk rising with duration and age and falling after stopping. Oestrogen-only HRT carries little or no increase. HRT tablets slightly increase the risk of blood clots and stroke, though the NHS says the risk is still very low, particularly under 60. Patches, sprays and gels do not increase clot risk. Discuss your own family and medical history with your prescriber.

Oestrogen side effects include headaches, breast tenderness, unexpected vaginal bleeding or spotting, nausea, mood changes, leg cramps, mild rash, diarrhoea and hair loss. Progestogen effects include period changes, spotting, headaches, breast tenderness, nausea, tiredness, mood changes and acne. The NHS says most settle within a few weeks and suggests continuing for at least three months if possible.

Irregular bleeding is common in the first months and usually settles within six months. Contact your GP if side effects are severe or last beyond three months, irregular bleeding continues beyond six months, bleeding becomes heavier, or bleeding returns after a period-free interval. Doses, types or delivery methods, for example tablets to patches, can be changed.

It is your choice whether and when to start. The NHS says there is no fixed limit on how long you can take HRT, and you continue only while benefits outweigh risks, with annual reviews; after about 60 the balance may shift. Most people need it for two to five years. You can stop suddenly or reduce gradually over three to six months to limit returning symptoms; if they persist beyond three months, speak to your GP about alternatives or a low-dose restart.

HRT is not contraception. You cannot take the combined pill and HRT together, though you may continue the combined pill until about 50 and then switch; the progestogen-only pill is compatible. The NHS says contraception is unnecessary after 55.

The NHS lists lifestyle changes, non-hormonal medicines, and herbal and complementary options for people who cannot or prefer not to take HRT. HRT is a prescription-only treatment. Suspected side effects can be reported through the Yellow Card scheme.