No, 40 is not too young. Perimenopause usually starts in your mid-40s, but it can begin in your late 30s or early 40s, and symptoms can show up years before your periods stop.
In short
- Perimenopause can start anywhere from the mid-30s to the mid-50s, most often in the mid-40s.
- It lasts about four years on average, sometimes up to eight.
- You don't need a blood test to start the conversation: your symptoms and your age matter most.
When does perimenopause usually start?
Menopause, the point when you haven't had a period for 12 months, usually happens between 45 and 55. Perimenopause is the stretch of years before it, when hormone levels rise and fall unevenly. It can begin as early as the mid-30s or as late as the mid-50s.
How long does it last?
On average about four years, but it can be a few months for some women and up to eight years for others.
What are the first signs?
Often changes to your cycle (shorter, longer, heavier or lighter periods), sleep problems, night sweats, mood changes or anxiety, and brain fog. Many women notice several small changes rather than one big one. Read more in Things nobody tells you about perimenopause.
Why do some doctors say “you're too young”?
Because menopause is often linked with the 50s, early perimenopause symptoms can be put down to stress or a busy life. If your body has changed and it doesn't feel like “just stress”, it's fair to ask again and to bring notes.
Do I need a hormone test?
Usually not. Hormone levels swing so much in perimenopause that one blood test can look normal. European guidance (EMAS) says that in otherwise healthy women over 45, perimenopause can be diagnosed from symptoms alone, without blood tests. Under 45, your doctor may suggest tests to rule out other causes.
What about menopause before 40 or 45?
Menopause before 45 is called early menopause, and before 40 premature menopause (premature ovarian insufficiency). If your periods stop or become very irregular before 40, see your doctor, because it matters for your bones and heart.
When to see a doctor
See your doctor if symptoms affect your life, if your periods are very heavy or come less than 21 days apart, if you bleed between periods or after sex, or if your periods stop before 40.
Bring notes. Your cycle dates and symptoms from the last few weeks make the conversation much easier. See How to talk to your doctor about perimenopause.
Frequently asked questions
Can I get pregnant in perimenopause?
Yes. It's less likely but possible while you still have periods, so use contraception if you don't want to get pregnant.
Is 38 too early for perimenopause?
It's less common but possible. Talk to your doctor, especially if your periods change a lot.
Do symptoms start before periods change?
They can. Sleep and mood changes often come first.
Notice your own pattern
Pausie helps you log your cycle and symptoms in a few taps, so you can show your doctor what has really changed. No account, and your diary stays on your phone.
This article is general information, not medical advice. Written by the Pausie team. Published and last reviewed 30 October 2026.
Sources
- World Health Organization: Menopause (fact sheet)
- EMAS Menopause Essentials: Diagnostic tests for menopause
- EMAS Menopause Essentials: Premature and early menopause
- Cleveland Clinic: Perimenopause