Collagen applied topically does not affect dhe collagen in your skin structure. It can only moisturize the skin and act as an occlusive ingredient to keep the water jn the skin. Therefore the skin may appear plumper. The ingested collagen may affect the skin structure, but since it’s a big protein, it will break down in small amino acids and they will go to different places in your body where a specif protein is needed. So, it won’t necessarily go to the skin and improve it. Unless your skin is the organ that needs the protein the most. But, this can work for any type of protein, not necessarily collagen, so my advice would be to get the right amount of proteins daily by food. If you can’t achieve that, then protein or collagen supplements can be an option