@cloudel - Collagen is part of the extracellular matrix that just cannot be replaced by putting on a topical cream. You have to stimulate production of it from the inside.
There are creams out there that claim to be able to do this. Just don’t buy any cream that actually contains collagen, because it will be useless for this.
Of course, protecting your skin from the sun and avoiding stress will help prevent you from losing pieces of your extracellular matrix to begin with. However, if you need to produce more collagen, I’ve heard that vitamin C helps boost production of it.
My dermatologist also told me about certain products that are good for stimulating production, so you might want to ask yours for professional advice before investing a lot of money into an anti-aging product.