You cannot put collagen back. You can only stop taking it out.

You started losing collagen in your twenties, and you have not stopped since. By the time you notice it in the mirror, a quarter of what you had may already be gone. The industry that has grown up around this fact is enormous. Powders in your coffee, capsules in your cabinet, peptide drinks at the checkout counter, creams that promise to put it back into the layer of skin no cream can reach. None of these are the same conversation as what your dermatologist can do in a clinic, and this article is not about that conversation. This article is about the jar on your counter. The jar on your counter is not putting collagen back into your skin. What you can do is stop the things that are taking it.

Here is what happens to the collagen in the powder. You stir it into your coffee and you drink it. Your stomach does not know it is supposed to be for your face. It does what it does to any protein you eat, which is break it apart into the smallest pieces it can and send those pieces into the bloodstream as raw material. From there your body sends them to wherever it is doing the most building at that moment. That means your muscles, the lining of your gut, your immune cells, the parts of you that are constantly tearing down and rebuilding. Your skin is on the list, but it is far down the list, because the collagen in your skin turns over slowly and quietly compared to the rest of you. The cream is a different problem. The collagen molecule is too large to cross the outer layer of your skin and reach the layer underneath where the actual collagen lives. The label can say what it wants. The molecule cannot get there.

The thing that takes the most collagen out of your skin is the sun. Not time, and not gravity. The sun. Ultraviolet light hits your face and it switches on a small set of enzymes whose only job is to cut collagen fibers. Every sunny lunch you eat outside, every walk to your car, every weekend at the beach you forgot the bottle, you are running those enzymes a little longer. The women who put sunscreen on every morning, year after year, have measurably less of this damage by the time it would have started to show. Not a little less. About a quarter less. That is the difference one habit makes.

The second thing that protects collagen is a small molecule that has been quietly proving itself in dermatology offices for forty years. It is a form of vitamin A. The strong version is something a doctor prescribes. The weaker version sits on the shelf next to the moisturizers, and your skin slowly converts it into the strong one. Both work in the same direction. They turn off the same enzymes the sun was turning on, the ones whose job is to cut your collagen. And on skin that has already been damaged by the sun, they help the cells underneath start making collagen again. It is the only thing in this article that does both. Everything else is one verb. This one is two.

So what is doing the taking?

The first is sugar. When your blood sugar runs high, the sugar molecules drift into the layer of your skin where the collagen lives, and they stick to the fibers and form small hard knots between them. Once a fiber is knotted up like that, your body cannot break it down and replace it the way it normally would. The damage just sits there, year after year. By the time you are in your seventies, the amount of it in your skin is about five times what it was in your twenties. The second is the life you are living. When you are under stress for long enough, your body keeps a hormone called cortisol running in your blood, and cortisol tells your fibroblasts to slow down. Doctors have known this for a long time. People whose bodies make too much cortisol on their own develop thinner skin that heals more slowly, and the changes look very much like aging. A stressful year is doing something to your face, and it is not your imagination.

The collagen in your skin is being made right now, by cells you have never seen, in the language your body has been speaking since you were born. It does not need a powder. It does not need a cream. It needs you not to undo it. A good sunscreen on your face every morning is doing more for your collagen than the most expensive thing on your bathroom counter. And the slowest, quietest changes you can make to your week are doing more than any of it. The body is not the problem. The body is the answer. Your job is to stop standing in its way.