What age does perimenopause start? At 35, at 40 and beyond, explained plainly

Something has shifted. Your periods aren't quite as regular as they were. You're sleeping badly, or feeling flat, or hot at odd moments. A friend says "sounds like perimenopause", and you think: at my age? So what age does perimenopause start?

For most women, perimenopause starts in their mid-40s. The Menopause Charity says symptoms usually start at around 45, and the average age of menopause is 51. But it can start sooner. Women's Health Concern, the patient arm of the British Menopause Society, says perimenopause can start in your late 30s or early 40s.

So yes, it can be perimenopause at 40, and sometimes even in your late 30s. This guide explains what's typical, what's early, and when to get checked.

Not sure if what you're feeling fits? Our free perimenopause symptoms checklist lets you tick off everything you've noticed and print a list to take to your GP. There's no sign-up.

What age does perimenopause start? The short answer

• Usually around 45. That's when symptoms usually start, says the Menopause Charity.
• Sometimes in your late 30s or early 40s. Women's Health Concern says it can start this early.
• Menopause itself usually happens between 45 and 55, the NHS says. The average age is 51, says the Menopause Charity.
• Before 45 is called early menopause. Before 40 is called premature ovarian insufficiency (POI). Both need a GP's help.

What is perimenopause?

Perimenopause is the time when your periods start to become irregular, as the NHS puts it. Your hormone levels begin to go up and down. Women's Health Concern says this is often when symptoms are most noticeable.

Perimenopause ends with your last period. You only know it was your last once you've gone 12 months without one. That point is menopause.

There's no routine test for perimenopause, the NHS says. A doctor will usually go by your age and your symptoms. If the words are confusing, our guide to perimenopause vs menopause explains the stages.

At what age does perimenopause start, according to research?

Two large studies give a sense of the typical age.

An older US study, the Massachusetts Women's Health Study, followed about 2,570 women. Half had started perimenopause by 47.5 (the median age). The median age of natural menopause was 51.3. The time in between was nearly 4 years.

A newer US study called SWAN looked at what happens when it starts earlier. In a 2017 SWAN paper, women who started youngest (from about 42 to 45) had the longest transition: a typical 8.6 years. Women who started latest (from about 49 onwards) had a typical 4.4 years.

So the earlier perimenopause starts, the longer it tends to last. Our guide to how long menopause lasts goes into this in more detail.

Perimenopause at 35

Perimenopause at 35 is possible, but it's less common. Women's Health Concern says it can start in your late 30s. The Menopause Charity says it's not unusual for some women to get symptoms this early.

The same charity warns that health professionals may not think of hormones as the main cause of symptoms in women in their late 30s or early 40s. So if you think it might be hormonal, say so plainly.

One thing matters more at this age than any other. If your periods stop or become irregular before 40, it isn't something to wait and see about. The British Menopause Society estimates about 1 in 100 women reach menopause before 40. This is POI, and it needs proper checks and usually treatment. Our guide to early menopause symptoms explains it.

Perimenopause at 40

Perimenopause at 40 is well within the normal range. Women's Health Concern says it can start in your early 40s.

What matters is whether your periods are changing or have stopped:

• If your periods are changing but still coming, and you have symptoms, this could be perimenopause. It's worth talking to your GP about your options.
• If your periods stop altogether between 40 and 45, that's called early menopause, the Menopause Charity says.

The British Menopause Society says women with early menopause get much the same advice as women with POI. That means considering hormone replacement until about 51, to help protect bones and heart, unless there's a medical reason not to. HRT is something to talk through with your GP.

Under 45, a GP may sometimes do blood tests, the NHS says. Over 45, Women's Health Concern says you usually don't need a blood test. Your symptoms and period changes are the best guide.

What decides when perimenopause starts for you?

No one can predict your exact age. But some things are linked to an earlier start. The NHS lists these for early menopause:

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

The SWAN research found the same pattern with smoking. Smokers typically started perimenopause about a year earlier. Women with a higher body weight tended to start later.

Women's Health Concern adds that research suggests Black and Hispanic women may reach menopause about two years earlier than White or Asian women.

What are the first signs of perimenopause?

The NHS says one of the first signs is usually a change to your periods. They might come more or less often, or be heavier or lighter. Our page on perimenopause period changes explains what's normal.

Other common symptoms the NHS lists include:

• hot flushes and night sweats
• sleep problems
• low mood, anxiety and mood swings
• problems with memory and concentration
• heart palpitations
• headaches and migraines
• muscle aches and joint pain

The NHS says symptoms usually last 7 to 9 years, sometimes longer, and can change over time. For the full picture, see our plain-English list of perimenopause symptoms.

It can help to write things down as they happen. Our free symptoms checklist is a simple way to do that.

Can you still get pregnant in perimenopause?

Yes. Brook, the sexual health charity, says you can still get pregnant until you reach menopause, or until 55, whichever comes first. It says it's important to keep using contraception even if your periods are irregular.

Women's Health Concern gives this guide on when you can stop:

• Under 50: keep using contraception until you've gone two years without a period.
• 50 or over: you can stop after one year without a period.

If your contraception hides your periods, ask whoever prescribes it when to stop. And the NHS points out that HRT is not contraception.

When to see your GP

You don't need to wait until things are bad. The NHS suggests seeing your GP if you think you have symptoms of perimenopause and want to know your options.

Please also see your GP if:

• your periods stop or become irregular before 40
• you have menopause symptoms, or your periods stop, before 45
• you're bleeding more, not less, than before
• you have palpitations
• your mood is low most of the time, or symptoms are affecting your work, sleep or relationships

Take your list of symptoms with you. If you're under 45, it's fine to ask, "Could this be early menopause?"

Related: early menopause symptoms, signs perimenopause is ending and perimenopause fatigue.

This page is general information, not medical advice. If you're worried about any symptom, please talk to your GP or pharmacist.