Early menopause and premature ovarian insufficiency (POI)

SASian Anderson, Writer and editor, MyGLP. Sources checked 5 November 2026.

The two definitions

The NHS page on early or premature menopause defines early menopause as periods stopping before 45, and premature menopause as periods stopping before 40. NICE uses the term premature ovarian insufficiency, or POI, for menopause before 40. A commentary on the NICE guideline in BMJ Sexual and Reproductive Health puts POI at about 1 in 100 women under 40.

Causes

Often no cause is found. The NHS lists these as raising the risk:

• a family history of early menopause
• starting periods early
• smoking
• being underweight
• radiotherapy or chemotherapy
• surgery to remove the ovaries, and some hormone medicines

A patient leaflet from University Hospital Southampton NHS Foundation Trust adds autoimmune conditions, such as thyroid or adrenal disease, and some infections, such as mumps.

Symptoms, and why they get missed

The symptoms match the usual menopause: hot flushes, night sweats, vaginal dryness, poor sleep, low mood, and problems with memory or concentration. At 35, the menopause is easy to overlook. If your periods have become rare or stopped and you have these symptoms, say so plainly and ask whether POI has been considered.

If you take a weight loss medicine, your periods may change for other reasons. Our periods guide explains what to expect and when changes need checking.

How NICE says POI is diagnosed

1. Your GP looks at your age, symptoms, family history and any treatment known to bring on the menopause.
2. If you are under 40 with few or no periods, NICE says you should be offered two FSH (follicle-stimulating hormone) blood tests, taken 4 to 6 weeks apart. FSH varies through the cycle, so one test is not enough.
3. If the diagnosis is unclear, NICE says you should be referred to a specialist in menopause or reproductive medicine.

The BMJ commentary notes FSH tests are kept for women under 40, and women aged 40 to 45 with symptoms and period changes, because results cannot be read properly if you take oestrogen or high-dose progestogen.

Why hormone replacement matters so much here

The NHS says early or premature menopause raises the risk of osteoporosis and cardiovascular disease. The Southampton leaflet adds stroke, memory problems and dementia to the list of risks linked to low oestrogen. Replacing hormones helps prevent osteoporosis, and the NHS says this matters most when periods stop before 45. That is why treatment is recommended even if symptoms are mild.

NICE says treatment is usually HRT or a combined hormonal contraceptive, and your GP should explain:

• HRT is not a contraceptive.
• HRT may be better for blood pressure than the combined pill.
• Both are good for bone health.
• Treatment should continue until at least the age of natural menopause.

The British Menopause Society consensus statement gives that age as about 51. After 51, you and your doctor decide about continuing in the same way as any woman at the usual age of menopause.

Is HRT riskier when you start young?

This worry stops many young women taking HRT. NICE says the risk of cardiovascular disease and breast cancer rises with age and is very low in women under 40. HRT in POI replaces hormones you would otherwise still have.

For early menopause at 40 to 44, the NICE discussion aid gives these breast cancer figures for women taking HRT for 10 years from 40, counted up to age 59:

NICE found no evidence to give equivalent figures for fractures or heart disease in this group. The full set of risks for women at the usual age is in our HRT in numbers guide.

Hormone treatment is not suitable for everyone. NICE gives the example of women with a history of breast cancer or another oestrogen-sensitive cancer. Then your GP should talk through other options and give you information on bone and heart health.

Protecting bones and heart alongside HRT

The NHS recommends regular exercise and calcium-rich foods. Our bone health guide covers calcium, vitamin D, weight-bearing exercise and when to ask for a bone density scan. Our heart health after menopause guide covers blood pressure, cholesterol and the NHS Health Check. If you are losing weight fast, read both. The bone guide explains how fast weight loss affects bone density.

Fertility and contraception

POI does not always mean the ovaries have stopped for good. The Southampton leaflet puts the chance of a natural pregnancy at about 5%, so you still need contraception if you do not want to get pregnant. HRT alone is not contraception.

If you want children, the NHS lists options including IVF with frozen or donor eggs, surrogacy and adoption. Ask for a referral to a fertility specialist early. Our fertility guide covers stopping a weight loss medicine before trying for a baby, and the contraception guide covers which methods stay reliable on a jab.

Support

The NHS says you can refer yourself to NHS talking therapies without seeing a GP first, and a specialist menopause centre is an option if symptoms persist. The Southampton leaflet points to the Daisy Network, a UK patient-run support group for women with POI.

Sources

1. Early or premature menopause (NHS)
2. Premature menopause (information for the public) (NICE)
3. Commentary on the NICE menopause guideline (BMJ Sexual and Reproductive Health, 2016)
4. Premature ovarian insufficiency: patient information (University Hospital Southampton NHS Foundation Trust)
5. BMS and WHC recommendations on HRT in menopausal women (British Menopause Society and Women's Health Concern)
6. Incidence of medical conditions with and without HRT: a discussion aid (NICE)
7. Benefits and risks of HRT (NHS)