Have your periods changed over the past few months? Shorter, longer, closer together, or on the contrary, absent for two months before coming back as before? You may have already heard the words "premenopause" or "perimenopause" without really knowing what they mean, or when they apply to you.

What this article explains: the difference between these three phases, what's actually happening in your body at each one, and how to know where you stand.

1- Premenopause: the very beginning, often invisible

Premenopause refers to the period before the first perceptible changes in your cycle. It generally begins between ages 40 and 45, sometimes earlier, and can last several years without any outward sign being visible.

During this phase, the ovaries keep functioning normally, but hormone production (estrogen and progesterone) starts to fluctuate more noticeably from one cycle to the next. Periods remain regular in most cases. It's a silent phase: the body is preparing for the transition before it becomes noticeable.

2- Perimenopause: the transition phase, what actually changes

Perimenopause is the phase that follows premenopause and precedes menopause itself. This is the stage where changes become concrete and observable. It lasts 4 years on average, but can range from a few months to 8 years depending on the person.

The most common signs:

• Cycles that get shorter or longer, sometimes unpredictably from one month to the next
• Flow that changes: heavier some months, lighter others
• Periods that skip a month and then return to normal the following month
• Hot flashes, sleep disturbances, vaginal dryness... and many other lesser-known signs, which we detail in our complete list of menopause symptoms

What truly characterizes perimenopause is unpredictability. Unlike a regular cycle where you roughly know what to expect, this phase doesn't follow a fixed logic. This unpredictability comes from a precise hormonal cascade. You can understand it in detail in our article on the real order in which hormones drop during perimenopause. It also makes day-to-day life harder to plan for, especially when it comes to managing period protection.

3- Menopause: a precise medical definition, not a feeling

Unlike the two previous phases, menopause isn't a period of time but a precise point in time. Its medical definition is clear: menopause is confirmed after 12 consecutive months without any period, with no other medical or hormonal cause explaining that absence.

In France, the average age of menopause is around 51. Once that 12-month mark is reached, we no longer talk about perimenopause: the transition is over, and postmenopause begins.

A cycle that returns after several months of absence doesn't mean you've gone backward: it's still perimenopause, as long as the 12 consecutive months haven't passed.

4- How to know where you stand

There's no single test that announces "you're in perimenopause" overnight. It's a gradual evolution, usually identified in hindsight, by observing your cycles over several months. A few concrete markers to help you:

• Track your cycles: length, flow volume, presence or absence of periods, month by month
• Spot the variations: a cycle that varies by more than 7 days from your usual pattern is a common sign of perimenopause
• Consider your age: perimenopause most often begins between 45 and 55, but it can start earlier
• See a doctor if needed: a gynecologist or midwife can confirm where you stand, especially if you're unsure or notice significant changes

If the symptoms of this transition affect your quality of life, menopause hormone therapy (HRT) can be considered with your doctor. We explain in detail why HRT was long criticized and what we know about it today, as well as what happens if you decide to stop it one day.

In summary

• Premenopause: the silent phase, with no visible change in your cycle
• Perimenopause: the transition phase, marked by unpredictable cycles
• Menopause: a precise point in time, 12 consecutive months without a period

This article lays the groundwork. To go further in this series on the hormonal transition: which hormones actually change and in what order, HRT, its controversy, and current recommendations, what happens when you stop HRT, and our complete list of menopause symptoms, known and lesser-known.

On a practical note: if your cycles become unpredictable, a reusable, high-capacity protection like La Cup Luneale means you don't have to plan for a flow that, by definition, can't be planned for. We detail all the reasons it's an ally during this period.

Premenopause, perimenopause, menopause: three stages of the same natural transition, easier to go through once you know how to name them. None of these phases is a condition to be treated: it's a change in the body that deserves to be understood, supported, and never minimized.