Does this sound like you?

Your moisturizer doesn't last until lunch. Your foundation sits on top of your skin instead of melting into it. A cream you've loved for years suddenly stings. You catch your reflection in a shop window and think: when did that happen?

When I asked women in their forties, fifties and sixties to describe their skin, they used the same handful of words. Dull. Dehydrated. Lined. Less firm. Saggy. And when I asked what they missed most about their skin at thirty, almost every one said the same two things: the glow, and the firmness.

I know those words from the inside. I used the same brand of skincare from the age of sixteen, for a quarter of a century. In my forties it simply stopped working. I added a serum, then a richer night cream, and my skin only got drier. Putting on foundation at fifty-five felt like painting over the Kalahari desert: cracked underneath, settling into lines that hadn't been there before.

If any of this is familiar, I want you to hear this first. You're not imagining it, and you haven't done anything wrong.

What's going on

Your skin is changing because your hormones are changing. That's the whole story in one sentence, and the rest of this module fills it in.

For most of your life, estrogen has been quietly telling your skin what to do: make your own oils, hold on to water, keep producing the collagen that gives your face its shape. Through perimenopause and menopause, estrogen falls. Your skin hasn't forgotten how to look after itself. It's simply getting fewer instructions.

That's why the changes often arrive together, and why they can feel so sudden:

• Dryness that no cream seems to fix, because your skin is making less of its own oil.
• Sensitivity, because the protective outer layer is thinner and lets more through.
• Dullness, because skin renews itself more slowly than it used to.
• Loss of firmness, because collagen is being replaced more slowly than it's broken down.
• Breakouts in your forties or fifties, because, in perimenopause especially, your hormones swing rather than fall in a straight line.

The products that worked at thirty were made for the skin you had at thirty. They're not failing you. They're simply answering a question your skin isn't asking anymore.