Why collagen matters when you turn 40

As oestrogen falls in perimenopause and menopause, collagen loss accelerates across your whole body. Here’s the evidence, and what to do about it.

You’ve probably heard the word collagen thrown around a lot but here’s what doesn’t get talked about nearly enough: collagen isn’t just a beauty ingredient. It’s one of the most important structural proteins in your body.

Perimenopause, the transition leading up to menopause, typically begins somewhere in the mid-to-late 40s, though for many women it starts earlier. This period is marked by a gradual but meaningful drop in oestrogen. Oestrogen is often associated with the menstrual cycle, but in reality: it affects your mood, your sleep, your metabolism, your bone density, your muscle mass and, you guessed it, your collagen.

One of the trickier parts of this life stage is that while your energy requirements go down slightly as you age, your need for key nutrients and protein goes up. It sounds contradictory, and it is. What it means in practice is that eating the way you did in your 30s may no longer be enough to cover your nutritional bases. And one of the most significant gaps that opens up during this period is collagen.

What is collagen, and why does it matter so much?

Collagen is the most abundant protein in the human body, making up roughly 30% of your total protein content. Think of it as the scaffolding that holds everything together: your skin, bones, cartilage, tendons, ligaments and even your gut lining. It’s what keeps your skin firm, your joints cushioned, your bones resilient and your muscles structurally supported.

Why does collagen decline faster after 40?

While your body produces collagen naturally, production actually starts to decline in your mid-20s, at a rate of roughly 1% per year. When oestrogen drops during perimenopause and menopause, collagen loss accelerates dramatically. Women can lose up to 30% of their skin collagen inthe first five years after menopause, and natural production continues to fall by around 2% per year from then on. This has implications and the effects can be felt across the whole body.

How collagen loss shows up across your body

Your joints are often where women feel this first: extra stiffness in the morning, or movements not quite as effortless as they used to and your structural bone integrity declines too, leading to density loss over time.

From our 40s, we naturally lose lean muscle mass at 1–2% per year, and collagen’s amino acids help maintain the connective tissue that supports it. Many women also notice their hair feeling thinner or their nails snapping more easily, and declining collagen is part of the explanation, as collagen’s amino acids are the building blocks for keratin, the protein that hair and nails are made of.

Finally, emerging research points to collagen’s role in supporting gut lining integrity and microbiome balance, something that matters even more when hormonal changes are already stirring up inflammation in our gut.

Can you get enough collagen from food?

The honest answer is: sort of, but it’s complicated. Your body can use the amino acids from collagen-rich foods to support its own collagen production. The best dietary sources include bone broth, oily fish, chicken and eggs, alongside vitamin C-rich foods such as citrus, kiwi, bell peppers and strawberries, which help with absorption.

Even so, hitting meaningful amounts through food alone is difficult, especially as absorption from the gut becomes less efficient with age. The collagen in food also has to be broken down, digested and rebuilt, so it doesn’t transfer directly into your skin or joints in the way we might imagine. This is where supplementation starts to make real sense, as a targeted way to fill the gap.

What to look for in a collagen supplement

The evidence is genuinely promising, especially for women over 40. Hydrolysed collagen peptides, collagen that has been broken down into smaller, more easily absorbed fragments, are the most well-studied form. But not all collagen supplements are created equal. Here’s what to look for:

• Choose hydrolysed collagen peptides. These are the most bioavailable form, so your body can actually absorb and use them more efficiently.
• Look for doses of 5–10g per day. This is what most skin and bone research is based on. Higher doses (above 10g) are typically used in muscle-recovery contexts.
• Always pair with vitamin C. Collagen synthesis cannot happen without it. Vitamin C is an essential cofactor in the process, so without it your body simply doesn’t have what it needs to put that collagen to work.
• Treat it as a long-term habit, not a short-term solution. Most studies showing meaningful results ran for at least 8–12 weeks, with bone-related benefits taking closer to 6–12 months.

Collagen isn’t just a trendy buzzword. It’s a protein your body genuinely depends on, one that declines faster in women than in men, and faster after 40 than at any other time. The good news is getting enough protein overall, eating collagen-supportive foods, reducing the things that accelerate collagen breakdown (excess sugar, smoking, excessive sun exposure) and considering a quality hydrolysed collagen supplement are all steps that make a real difference.