QUOTE(boo! grr... @ Nov 24 2006, 11:29 PM)

but using too much chemical, would it harm ur skin?
You should never use too many potentially harmful products chock-full of chemicals, but if the products are out there for you to use, you should expect that you can use thm regularly (according to their instructions), and for nothing harmful to happen. That is, unless you're allergic or sensitive to the product.
I think switching products around once in a while is good, there shouldn't be a problem.