“Am I too young for this?” It’s one of the most common questions women ask when their body starts to feel different. Here’s what you need to know about when perimenopause starts, the very first signs and how long it usually lasts.
Quick answer: perimenopause usually starts in your 40s, most often in your mid-40s, but it can begin in your late 30s. It lasts about four years on average, and ends at menopause, which most women reach at around 51.
What age does perimenopause usually start?
Most women notice the first changes somewhere between 40 and 47. For some, it begins in the late 30s; for others, not until about 50. There’s no exact age, because every woman’s body follows its own timeline.
What affects when it starts?
- Your family: women often go through menopause at a similar age to their mother and sisters.
- Smoking: smokers tend to reach menopause one to two years earlier.
- Medical treatments: surgery to remove the ovaries, some cancer treatments and certain other conditions can bring it on earlier.
- Hysterectomy: if your womb has been removed but not your ovaries, you won’t have periods to track, so other symptoms may be the first clue.
The first signs of perimenopause
The earliest signs are often subtle and easy to put down to stress or a busy life:
- Periods that become a few days shorter, longer, heavier or less predictable
- Worse PMS, sore breasts or bloating
- Waking in the night, often around 3 or 4am
- New anxiety, irritability or low mood
- Feeling warm at night or having the odd hot flush
- Feeling more tired than usual, or noticing brain fog
For the full list, see our guide to 17 perimenopause symptoms.
How long does perimenopause last?
On average, perimenopause lasts around four years, but it varies a lot. For some women it’s a few months; for others it’s eight to ten years. It’s usually split into two stages:
- Early perimenopause: your periods are still fairly regular, but your cycle length starts to change by a week or more.
- Late perimenopause: you start to skip periods, with gaps of two months or more between them. Hot flushes and night sweats are often strongest at this stage.
Perimenopause vs menopause: what’s the difference?
Perimenopause is the transition, when hormones fluctuate and you still have periods, even if they’re irregular. Menopause is a single point in time: 12 months in a row without a period. After that, you’re postmenopausal.
- Average age of menopause: around 51
- Early menopause: between 40 and 45
- Premature menopause (premature ovarian insufficiency): before 40. If you think this could be you, see your doctor, because treatment is important for your long-term health.
Is there a test for perimenopause?
For women over 45 with typical symptoms, a diagnosis is usually based on your symptoms and periods, without a blood test. Hormone levels go up and down so much during perimenopause that a single test often isn’t reliable. If you’re younger, your doctor may suggest tests to rule out other causes, such as thyroid problems.
What can you do now?
You can’t change when perimenopause starts, but you can make it a much easier ride:
- Track your cycle and symptoms for a few months, so you can spot patterns and talk to your doctor with confidence.
- Start strength training to protect your muscles and bones. Our beginner’s guide shows you how.
- Eat enough protein, roughly 25–35 g per meal. Start with these high-protein breakfasts.
- Walk daily and protect your sleep. Try our 30-day walking plan.
- Talk to your doctor about treatment options, including HRT, if your symptoms are affecting your life.
Frequently asked questions
Can perimenopause start at 35?
It’s less common, but yes, some women notice changes in their mid to late 30s. If you’re under 40 and your periods stop or become very irregular, see your doctor.
What’s the youngest age for perimenopause?
Most women start in their 40s. When periods stop before 40, doctors call it premature ovarian insufficiency, which needs medical support.
How do I know when perimenopause is over?
Once you’ve gone 12 months without a period, you’ve reached menopause, and perimenopause is over.
The bottom line
If you’re in your 40s and your body feels different, you’re not imagining it, and you’re definitely not alone. Learn the signs, look after your strength and sleep, and get support early. For simple first steps, download our free Fit After 40 Starter Kit.
This article is for general information only and isn’t medical advice.
