Alcohol can strip your skin of natural protective barriers exposing it to viruses, bacteria and mold. Finally, there's collagen. But wait, didn't I just tell you collagen is an important part of your skin - that it gives your skin strength and firmness? Yep, I sure did. But here's the thing. Collagen molecules are too large to be absorbed by your skin when applied topically. Manufacturers use it as an ingredient in their skin care products to fool you into believing their product is superior.