The French word for glue is col. Think of a collage, a picture made up of lots of other pictures glued together -that’s where it gets its name from. Collagen comes from the same root as well. It is the glue that holds the skin together.
What it actually is is a long protein molecule. Its structure is a bit like a spring in some ways, and it certainly imparts the skin with springiness. You can buy instruments that measure the skin’s springiness. They work by measuring how much energy the skin can muster to return to its original position after it has been perturbed, and this is pretty much a measure of how much collagen the skin possesses.
Well actually that is a bit of a simplification. The total amount of collagen isn’t so important, it is more a question of how long the protein chains in the collagen are. Longer chains give you firm wrinkle free skin. Shorter chains are not so efficient at gluing the skin together so the skin loses its springiness. The skin is continually breaking down and reassembling its collagen, but as time goes on there is a tendency for the breaking down process to outstrip the rebuilding process.
Once this all came to be understood, it wasn’t long before someone hit on the idea of adding collagen to a skin cream to replace the collagen that was being lost over time. You can’t fault the logic, but unfortunately life proved to be more complicated than that, as it often does. Collagen is present throughout the skin, but it plays its biggest role in maintaining the skin’s integrity deep down in the dermis. If you could get collagen down that far it might just do some good. But getting molecules through the skin is not easy, and collagen certainly will not penetrate the skin at all.
So are all the creams that claim to contain collagen complete rubbish then? Well as it happens collagen does have some benefits on the surface of the skin. Like a lot of water soluble polymers it shrinks when it drys out. If you put a thin layer on your skin, as it dries it will shrink giving a slight temporary shrinking effect. You can achieve the same thing with quite a wide range of materials, but collagen certainly works. If you look carefully at the claims on the pack of most creams that contain collagen you will find that they are quite vague. Yes, collagen has some benefits but putting it on your skin won’t actually do anything to replace your missing collagen.
I did once see a product that tried to overcome the formidable barrier that the skin presents by putting the collagen in a sachet. You made it up in water and drank it. Could this work? No. Collagen is a protein and the digestive system quickly breaks proteins down to their building blocks so there is no possibility of this approach doing your skin any good at all. And in any case, a burger contains plenty of collagen so an extra supplement is of no use at all.
Collagen is a useful substrate for use in cosmetic surgery where the surgeons overcome the skin’s normally impressive barrier properties by simply cutting into it or by using injections. It isn’t completely useless in skin creams, but its use is a bit of a gimmick.
Thanks to Salvatore Vuono for the use of the image. You can see more from his portfolio at